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The energy efficiency in transport is the useful travelled
distance Distance is a numerical or occasionally qualitative measurement of how far apart objects or points are. In physics or everyday usage, distance may refer to a physical length or an estimation based on other criteria (e.g. "two counties over"). ...
, of passengers, goods or any type of load; divided by the total
energy In physics, energy (from Ancient Greek: ἐνέργεια, ''enérgeia'', “activity”) is the quantitative property that is transferred to a body or to a physical system, recognizable in the performance of work and in the form of ...
put into the transport
propulsion Propulsion is the generation of force by any combination of pushing or pulling to modify the translational motion of an object, which is typically a rigid body (or an articulated rigid body) but may also concern a fluid. The term is derived f ...
means. The energy input might be rendered in several different types depending on the type of propulsion, and normally such energy is presented in liquid fuels,
electrical energy Electrical energy is energy related to forces on electrically charged particles and the movement of electrically charged particles (often electrons in wires, but not always). This energy is supplied by the combination of electric current and elect ...
or
food energy Food energy is chemical energy that animals (including humans) derive from their food to sustain their metabolism, including their muscular activity. Most animals derive most of their energy from aerobic respiration, namely combining the carbohy ...
. The energy efficiency is also occasionally known as
energy intensity Energy intensity is a measure of the energy inefficiency of an economy. It is calculated as units of energy per unit of GDP. * High energy intensities indicate a high price or cost of converting energy into GDP. * Low energy intensity indica ...
. The
inverse Inverse or invert may refer to: Science and mathematics * Inverse (logic), a type of conditional sentence which is an immediate inference made from another conditional sentence * Additive inverse (negation), the inverse of a number that, when a ...
of the energy efficiency in transport, is the energy consumption in transport. Energy efficiency in transport is often described in terms of
fuel consumption A fuel is any material that can be made to react with other substances so that it releases energy as thermal energy or to be used for work. The concept was originally applied solely to those materials capable of releasing chemical energy but ...
, fuel consumption being the reciprocal of fuel economy. Nonetheless, fuel consumption is linked with a means of propulsion which uses liquid fuels, whilst energy efficiency is applicable to any sort of propulsion. To avoid said confusion, and to be able to compare the energy efficiency in any type of vehicle, experts tend to measure the energy in the
International System of Units The International System of Units, known by the international abbreviation SI in all languages and sometimes pleonastically as the SI system, is the modern form of the metric system and the world's most widely used system of measurement. ...
, i.e.,
joule The joule ( , ; symbol: J) is the unit of energy in the International System of Units (SI). It is equal to the amount of work done when a force of 1 newton displaces a mass through a distance of 1 metre in the direction of the force appli ...
s. Therefore, in the International System of Units, the energy efficiency in transport is measured in terms of metre per joule, or m/J, whilst the energy consumption in transport is measured in terms of joules per metre, or J/m. The more efficient the vehicle, the more metres it covers with one joule (more efficiency), or the fewer joules it uses to travel over one metre (less consumption). The energy efficiency in transport largely varies by means of transport. Different types of
transport Transport (in British English), or transportation (in American English), is the intentional movement of humans, animals, and goods from one location to another. Modes of transport include air, land ( rail and road), water, cable, pipelin ...
range from some hundred
kilojoules The joule ( , ; symbol: J) is the unit of energy in the International System of Units (SI). It is equal to the amount of work done when a force of 1 newton displaces a mass through a distance of 1 metre in the direction of the force applie ...
per kilometre (kJ/km) for a
bicycle A bicycle, also called a pedal cycle, bike or cycle, is a human-powered or motor-powered assisted, pedal-driven, single-track vehicle, having two wheels attached to a frame, one behind the other. A is called a cyclist, or bicyclist. B ...
to tens of megajoules per kilometre (MJ/km) for a
helicopter A helicopter is a type of rotorcraft in which lift and thrust are supplied by horizontally spinning rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forward, backward and laterally. These attribu ...
. Via type of fuel used and rate of fuel consumption, energy efficiency is also often related to operating cost ($/km) and environmental emissions (e.g. CO/km).


Units of measurement

In the
International System of Units The International System of Units, known by the international abbreviation SI in all languages and sometimes pleonastically as the SI system, is the modern form of the metric system and the world's most widely used system of measurement. ...
, the energy efficiency in transport is measured in terms of metre per joule, or m/J. Nonetheless, several conversions are applicable, depending on the unit of distance and on the unit of energy. For liquid fuels, normally the quantity of energy input is measured in terms of the liquid's volume, such as litres or gallons. For propulsion which runs on electricity, normally
kW·h A kilowatt-hour ( unit symbol: kW⋅h or kW h; commonly written as kWh) is a unit of energy: one kilowatt of power for one hour. In terms of SI derived units with special names, it equals 3.6 megajoules (MJ). Kilowatt-hours are a common bi ...
is used, while for any type of human-propelled vehicle, the energy input is measured in terms of
Calorie The calorie is a unit of energy. For historical reasons, two main definitions of "calorie" are in wide use. The large calorie, food calorie, or kilogram calorie was originally defined as the amount of heat needed to raise the temperature of o ...
s. It is typical to convert between different types of energy and units. For
passenger transport Transport (in British English), or transportation (in American English), is the intentional movement of humans, animals, and goods from one location to another. Modes of transport include air, land (rail and road), water, cable, pipeline, a ...
, the energy efficiency is normally measured in terms of passengers times distance per unit of energy, in the SI, passengers metres per joule (pax.m/J); while for
cargo transport Freight transport, also referred as ''Freight Forwarding'', is the physical process of transporting Commodity, commodities and merchandise goods and cargo. The term shipping originally referred to transport by sea but in American English, it h ...
the energy efficiency is normally measured in terms of mass of transported cargo times distance per unit of energy, in the SI, kilograms metres per joule (kg.m/J). Volumetric efficiency with respect to vehicle capacity may also be reported, such as passenger-mile per gallon (PMPG), obtained by multiplying the
miles per gallon The fuel economy of an automobile relates distance traveled by a vehicle and the amount of fuel consumed. Consumption can be expressed in terms of volume of fuel to travel a distance, or the distance traveled per unit volume of fuel consumed. S ...
of
fuel A fuel is any material that can be made to react with other substances so that it releases energy as thermal energy or to be used for work. The concept was originally applied solely to those materials capable of releasing chemical energy b ...
by either the passenger capacity or the average occupancy. The occupancy of personal vehicles is typically lower than capacity by a considerable degree and thus the values computed based on capacity and on occupancy will often be quite different.


Typical conversions into SI unit


Liquid fuels

Energy efficiency is expressed in terms of fuel economy: * distance per vehicle per unit fuel volume; e.g., km/L or miles per gallon (US or imperial). * distance per vehicle per unit fuel mass; e.g., km/kg. * distance per vehicle per unit energy; e.g.,
miles per gallon equivalent Miles per gallon gasoline equivalent (MPGe or MPGge) is a measure of the average distance traveled per unit of energy consumed. MPGe is used by the United States Environmental Protection Agency (EPA) to compare energy consumption of alternative ...
(mpg-e). Energy consumption (reciprocal efficiency) is expressed terms of fuel consumption: * volume of fuel (or total energy) consumed per unit distance per vehicle; e.g. l/100 km or MJ/100 km. * volume of fuel (or total energy) consumed per unit distance per passenger; e.g., l/(100 passenger·km). * volume of fuel (or total energy) consumed per unit distance per unit mass of
cargo Cargo consists of bulk goods conveyed by water, air, or land. In economics, freight is cargo that is transported at a freight rate for commercial gain. ''Cargo'' was originally a shipload but now covers all types of freight, including tra ...
transported; e.g., l/100 kg·km or MJ/t·km.


Electricity

Electricity consumption: * electrical energy used per vehicle per unit distance; e.g., kW·h/100 km. Producing electricity from fuel requires much more
primary energy Primary energy (PE) is an energy form found in nature that has not been subjected to any human engineered conversion process. It is energy contained in raw fuels, and other forms of energy, including waste, received as input to a system. Prim ...
than the amount of electricity produced.


Food energy

Energy consumption: * calories burnt by the body's metabolism per kilometre; e.g., Cal/km. * calories burnt by the body's metabolism per mile; e.g., Cal/miles.


Land Passenger Transport


Table Overview

In the following table the energy efficiency and energy consumption for different types of passenger land vehicles and modes of transport, as well as standard occupancy rates, are presented. The sources for these figures are in the correspondent section for each vehicle, in the following article. The conversions amongst different types of units, are well known in the art. For the conversion amongst units of energy in the following table, 1 litre of petrol amounts to 34.2 MJ, 1
kWh A kilowatt-hour (unit symbol: kW⋅h or kW h; commonly written as kWh) is a unit of energy: one kilowatt of power for one hour. In terms of SI derived units with special names, it equals 3.6 megajoules (MJ). Kilowatt-hours are a common bill ...
amounts to 3.6 MJ and 1 kilocalorie amounts to 4184 J. For the car occupation ratio, the value of 1.2 passengers per automobile was considered. Nonetheless, in Europe this value slightly increases to 1.4. The sources for conversions amongst units of measurements appear only of the first row.


Land transport means


Walking

A person
walking Walking (also known as ambulation) is one of the main gaits of terrestrial locomotion among legged animals. Walking is typically slower than running and other gaits. Walking is defined by an ' inverted pendulum' gait in which the body vaults ...
at requires approximately of food energy per hour, which is equivalent to 4.55 km/MJ. of petrol contains about of energy, so this is approximately equivalent to .


Velomobile

Velomobiles (enclosed recumbent bicycles) have the highest energy efficiency of any known mode of personal transport because of their small frontal area and aerodynamic shape. At a speed of , the velomobile manufacturer WAW claims that only 0.5 kW·h (1.8 MJ) of energy per 100 km is needed to transport the passenger (= 18 J/m). This is around (20%) of what is needed to power a standard upright bicycle without aerodynamic cladding at same speed, and (2%) of that which is consumed by an average fossil fuel or electric car (the velomobile efficiency corresponds to 4700 miles per US gallon, 2000 km/L, or 0.05 L/100 km). Real energy from food used by human is 4–5 times more. Unfortunately their energy efficiency advantage over bicycles becomes smaller with decreasing speed and disappears at around 10 km/h where power needed for velomobiles and triathlon bikes are almost the same.


Bicycle

A standard lightweight, moderate-speed bicycle is one of the most energy-efficient forms of transport. Compared with walking, a cyclist riding at requires about half the food energy per unit distance: 27 kcal/km, per 100 km, or 43 kcal/mi. This converts to about . This means that a bicycle will use between 10 and 25 times less energy per distance travelled than a personal car, depending on fuel source and size of the car. This figure does depend on the speed and mass of the rider: greater speeds give higher
air drag In fluid dynamics, drag (sometimes called air resistance, a type of friction, or fluid resistance, another type of friction or fluid friction) is a force acting opposite to the relative motion of any object moving with respect to a surrounding flu ...
and heavier riders consume more energy per unit distance. In addition, because bicycles are very lightweight (usually between 7–15 kg) this means they consume very low amounts of materials and energy to manufacture. In comparison to an automobile weighing 1500 kg or more, a bicycle typically requires 100–200 times less energy to produce than an automobile. In addition, bicycles require less space both to park and to operate and they damage road surfaces less, adding an infrastructural factor of efficiency.


Motorised bicycle

A motorised bicycle allows human power and the assistance of a engine, giving a range of . Electric pedal-assisted bikes run on as little as per 100 km, while maintaining speeds in excess of . These best-case figures rely on a human doing 70% of the work, with around per 100 km coming from the motor. This makes an electric bicycle one of the most efficient possible motorised vehicles, behind only a motorised velomobile and an electric unicycle (EUC).


Electric kick scooter

Electric kick scooters, such as those used by scooter-sharing systems like
Bird Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweig ...
or Lime, typically have a maximum range of under and a maximum speed of roughly . Intended to fit into a last mile niche and be ridden in bike lanes, they require little skill from the rider. Because of their light weight and small motors, they are extremely energy-efficient with a typical energy efficiency of 1.1 kW⋅h (4.0 MJ) per 100 km (1904 MPGe 810 km/L 0.124 L/100 km), even more efficient than bicycles and walking. However, as they must be recharged frequently, they are often collected overnight with motor vehicles, somewhat negating this efficiency. The lifecycle of electric scooters is also notably shorter than that of bicycles, often reaching only a single digit number of years.


Electric Unicycle

An electric unicycle (EUC) cross electric skateboard variant called the Onewheel Pint can carry a 50 kg person 21.5 km at an average speed of 20 km/h. The battery holds 148Wh. Without taking energy lost to heat in the charging stage into account, this equates to an efficiency of 6.88Wh/km or 0.688kWh/100 km. Additionally, with regenerative braking as a standard design feature, hilly terrain would have less impact on an EUC compared to a vehicle with friction brakes such as a push bike. This combined with the single wheel ground interaction may make the EUC the most efficient known vehicle at low speeds (below 25 km/h), with the velomobile overtaking the position as most efficient at higher speeds due to superior aerodynamics.


Automobiles

Automobiles are generally inefficient when compared to other modes of transport, due to the relatively high weight of the vehicle compared to its occupants. Automobile
fuel efficiency Fuel efficiency is a form of thermal efficiency, meaning the ratio of effort to result of a process that converts chemical potential energy contained in a carrier (fuel) into kinetic energy or work. Overall fuel efficiency may vary per device ...
is most commonly expressed in terms of the volume of fuel consumed per one hundred kilometres (l/100 km), but in some countries (including the United States, the United Kingdom and India) it is more commonly expressed in terms of the distance per volume fuel consumed (km/L or
miles per gallon The fuel economy of an automobile relates distance traveled by a vehicle and the amount of fuel consumed. Consumption can be expressed in terms of volume of fuel to travel a distance, or the distance traveled per unit volume of fuel consumed. S ...
). This is complicated by the different energy content of fuels such as petrol and diesel. The
Oak Ridge National Laboratory Oak Ridge National Laboratory (ORNL) is a U.S. multiprogram science and technology national laboratory sponsored by the U.S. Department of Energy (DOE) and administered, managed, and operated by UT–Battelle as a federally funded research an ...
(ORNL) states that the energy content of unleaded petrol is 115,000 British thermal unit (BTU) per US gallon (32 MJ/L) compared to 130,500 BTU per US gallon (36.4 MJ/L) for diesel. Due to the efficiency of electric motors, electric cars are much more efficient than their internal combustion engine counterparts, consuming on the order of 38
megajoule The joule ( , ; symbol: J) is the unit of energy in the International System of Units (SI). It is equal to the amount of work done when a force of 1 newton displaces a mass through a distance of 1 metre in the direction of the force applied ...
s (38 000 kJ) per 100 km in comparison to 142 megajoules per 100 km for combustion powered cars. A second important consideration is the energy costs of producing energy. Bio-fuels,
electricity Electricity is the set of physical phenomena associated with the presence and motion of matter that has a property of electric charge. Electricity is related to magnetism, both being part of the phenomenon of electromagnetism, as describe ...
and
hydrogen Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-to ...
, for instance, have significant energy inputs in their production.
Hydrogen production Hydrogen production is the family of industrial methods for generating hydrogen gas. As of 2020, the majority of hydrogen (∼95%) is produced from fossil fuels by steam reforming of natural gas and other light hydrocarbons, partial oxidation of ...
efficiency are 50–70% when produced from natural gas, and 10–15% from electricity. The efficiency of hydrogen production, as well as the energy required to store and transport hydrogen, must to be combined with the vehicle efficiency to yield net efficiency. Because of this, hydrogen automobiles are one of the least efficient means of passenger transport, generally around 50 times as much energy must be put into the production of hydrogen compared to how much is used to move the car. A third consideration to take into account when calculating energy efficiency of automobiles is the occupancy rate of the vehicle. Although the consumption per unit distance per vehicle increases with increasing number of passengers, this increase is slight compared to the reduction in consumption per unit distance per passenger. This means that higher occupancy yields higher energy efficiency per passenger. Automobile occupancy varies across regions. For example, the estimated average occupancy rate is about 1.3 passengers per car in the San Francisco Bay Area, while the 2006 UK estimated average is 1.58. Fourth, the energy needed to build and maintain roads is an important consideration, as is the energy returned on energy invested (EROEI). Between these two factors, roughly 20% must be added to the energy of the fuel consumed, to accurately account for the total energy used. Finally, vehicle energy efficiency calculations would be misleading without factoring the energy cost of producing the vehicle itself. This initial energy cost can of course be depreciated over the life of the vehicle to calculate an average energy efficiency over its effective life span. In other words, vehicles that take a lot of energy to produce and are used for relatively short periods will require a great deal more energy over their effective lifespan than those that do not, and are therefore much less energy efficient than they may otherwise seem. Hybrid and electric cars use less energy in their operation than comparable petroleum-fuelled cars but more energy is used to manufacture them, so the overall difference would be less than immediately apparent. Compare, for example, walking, which requires no special equipment at all, and an automobile, produced in and shipped from another country, and made from parts manufactured around the world from raw materials and minerals mined and processed elsewhere again, and used for a limited number of years. According to the French energy and environment agency ADEME, an average motor car has an embodied energy content of 20,800 kWh and an average electric vehicle amounts to 34,700 kWh. The electric car requires nearly twice as much energy to produce, primarily due to the large amount of mining and purification necessary for the rare earth metals and other materials used in lithium-ion batteries and in the electric drive motors. This represents a significant portion of the energy used over the life of the car (in some cases nearly as much as energy that is used through the fuel that is consumed, effectively doubling the car's per-distance energy consumption), and cannot be ignored when comparing automobiles to other transport modes. As these are average numbers for French automobiles and they are likely to be significantly larger in more auto-centric countries like the United States and Canada, where much larger and heavier cars are more common. Driving practices and vehicles can be modified to improve their energy efficiency by about 15%. On a percentage basis, if there is one occupant in an automobile, only about 0.5% of the total energy used is used to move the person in the car, while the remaining 99.5% (about 200 times more) is used to move the car itself.


Example consumption figures

* Solar cars are electric vehicles that use little or no externally supplied energy other than from sunlight, charging the batteries from built-in solar panels, and typically use less than 3 kW·h per 100 miles (67 kJ/km or 1.86 kW·h/100 km). Most of these cars are race cars designed for competition and not for passenger or utility use. However several companies are designing solar cars for public use. As of December 2021, none have yet been released. * The four passenger
GEM A gemstone (also called a fine gem, jewel, precious stone, or semiprecious stone) is a piece of mineral crystal which, in cut and polished form, is used to make jewelry or other adornments. However, certain rocks (such as lapis lazuli, opal, an ...
NEV uses , which equates to 2.6 kW·h/100 km per person when fully occupied, albeit at only . * The General Motors EV1 was rated in a test with a charging efficiency of 373 Wh-AC/mile or 23 kWh/100 km approximately equivalent to for petroleum-fuelled vehicles. * Chevrolet Volt in full electric mode uses , meaning it may approach or exceed the energy efficiency of walking if the car is fully occupied with 4 or more passengers, although the relative emissions produced may not follow the same trends if analysing environmental impacts. * The Daihatsu Charade 993cc turbo diesel (1987–1993) won the most fuel efficient vehicle award for going round the United Kingdom consuming an average of . It was surpassed only recently by the VW Lupo 3 L which consumes about . Both cars are rare to find on the popular market. The Daihatsu had major problems with rust and structural safety which contributes to its rarity and the quite short production run. * The Volkswagen Polo 1.4 TDI Bluemotion and the SEAT Ibiza 1.4 TDI Ecomotion, both rated at (combined) were the most fuel efficient petroleum-fuelled cars on sale in the UK as of 22 March 2008. * Honda Insight – achieves under real-world conditions. *
Honda Civic Hybrid The is a series of automobiles manufactured by Honda since 1972. Since 2000, the Civic has been categorized as a compact car, while previously it occupied the subcompact class. , the Civic is positioned between the Honda Fit/City and Honda Ac ...
regularly averages around . * 2012 Cadillac CTS-V Wagon 6.2 L Supercharged, * 2012 Bugatti Veyron, * 2018
Honda Civic The is a series of automobiles manufactured by Honda since 1972. Since 2000, the Civic has been categorized as a compact car, while previously it occupied the subcompact class. , the Civic is positioned between the Honda Fit/City and Honda A ...
: * 2017 Mitsubishi Mirage: * 2017 Hyundai Ioniq hybrid: * 2017 Toyota Prius: (Eco trim) * 2018 Nissan Leaf: /100 mi (671 kJ/km) or 112 MPGe * 2017 Hyundai Ioniq EV: /100 mi (560 kJ/km) or 136 MPGe *2020 Tesla model 3: 24 kWh (86.4 MJ)/100 mi (540 kJ/km) or 141 MPGe


Trains

Train In rail transport, a train (from Old French , from Latin , "to pull, to draw") is a series of connected vehicles that run along a railway track and transport people or freight. Trains are typically pulled or pushed by locomotives (often ...
s are in general one of the most efficient means of transport for
freight Cargo consists of bulk goods conveyed by water, air, or land. In economics, freight is cargo that is transported at a freight rate for commercial gain. ''Cargo'' was originally a shipload but now covers all types of freight, including tran ...
and
passenger A passenger (also abbreviated as pax) is a person who travels in a vehicle, but does not bear any responsibility for the tasks required for that vehicle to arrive at its destination or otherwise operate the vehicle, and is not a steward. Th ...
s. Advantages of trains include low friction of steel wheels on steel rails, as well as an intrinsic high occupancy rate. Train lines are typically used to serve urban or inter-urban transit applications where their capacity utilization is maximized. Efficiency varies significantly with passenger loads, and losses incurred in electricity generation and supply (for electrified systems), and, importantly, end-to-end delivery, where stations are not the originating final destinations of a journey. While
electric motor An electric motor is an electrical machine that converts electrical energy into mechanical energy. Most electric motors operate through the interaction between the motor's magnetic field and electric current in a wire winding to generate f ...
s used in most passenger trains are more efficient than
internal combustion engine An internal combustion engine (ICE or IC engine) is a heat engine in which the combustion of a fuel occurs with an oxidizer (usually air) in a combustion chamber that is an integral part of the working fluid flow circuit. In an internal co ...
s, power generation in
thermal power plant A thermal power station is a type of power station in which heat energy is converted to electrical energy. In a steam-generating cycle heat is used to boil water in a large pressure vessel to produce high-pressure steam, which drives a steam ...
s is limited to (at best)
Carnot efficiency A Carnot cycle is an ideal thermodynamic cycle proposed by French physicist Sadi Carnot in 1824 and expanded upon by others in the 1830s and 1840s. By Carnot's theorem, it provides an upper limit on the efficiency of any classical thermodynam ...
and there are
transmission loss Transmission loss (TL) in general describes the accumulated decrease in intensity of a waveform energy as a wave propagates outwards from a source, or as it propagates through a certain area or through a certain type of structure. It is a termino ...
es on the way from the power plant to the train. Switzerland, which has electrified virtually its entire railway network (
heritage railway A heritage railway or heritage railroad (US usage) is a railway operated as living history to re-create or preserve railway scenes of the past. Heritage railways are often old railway lines preserved in a state depicting a period (or periods) i ...
s like the Dampfbahn Furka-Bergstrecke being notable exceptions), derives much of the electricity used by trains from
hydropower Hydropower (from el, ὕδωρ, "water"), also known as water power, is the use of falling or fast-running water to produce electricity or to power machines. This is achieved by converting the gravitational potential or kinetic energy of ...
, including
pumped hydro storage Pumped-storage hydroelectricity (PSH), or pumped hydroelectric energy storage (PHES), is a type of hydroelectric energy storage used by electric power systems for load balancing. The method stores energy in the form of gravitational poten ...
. While the mechanical efficiency of the turbines involved is comparatively high, pumped hydro involves energy losses and is only cost effective as it can consume energy during times of excess production (leading to low or even negative
spot price In finance, a spot contract, spot transaction, or simply spot, is a contract of buying or selling a commodity, security or currency for immediate settlement (payment and delivery) on the spot date, which is normally two business days after the ...
s) and release the energy again during high-demand times.Yang, Chi-Jen
Pumped Hydroelectric Storage
Duke University Duke University is a private research university in Durham, North Carolina. Founded by Methodists and Quakers in the present-day city of Trinity in 1838, the school moved to Durham in 1892. In 1924, tobacco and electric power industrialist Jam ...
. Accessed: 12 February 2012.
with some sources claiming up to 87%. Actual consumption depends on gradients, maximum speeds, and loading and stopping patterns. Data produced for the European MEET project (Methodologies for Estimating Air Pollutant Emissions) illustrate the different consumption patterns over several track sections. The results show the consumption for a German ICE high-speed train varied from around . The Siemens Velaro D type ICE trains seat 460 (16 of which in the
restaurant car A dining car (American English) or a restaurant car (British English), also a diner, is a railroad passenger car that serves meals in the manner of a full-service, sit-down restaurant. It is distinct from other railroad food service cars that d ...
) in their 200-meter length edition of which two can be coupled together. Per
Deutsche Bahn The (; abbreviated as DB or DB AG) is the national railway company of Germany. Headquartered in the Bahntower in Berlin, it is a joint-stock company ( AG). The Federal Republic of Germany is its single shareholder. describes itself as the ...
calculations, the energy used per 100 seat-km is the equivalent of of gasoline (). The data also reflects the weight of the train per passenger. For example,
TGV The TGV (french: Train à Grande Vitesse, "high-speed train"; previously french: TurboTrain à Grande Vitesse, label=none) is France's intercity high-speed rail service, operated by SNCF. SNCF worked on a high-speed rail network from 1966 to 19 ...
double-deck Duplex trains use lightweight materials, which keep axle loads down and reduce damage to track and also save energy. The TGV mostly runs on French nuclear fission power plants which are again limited – as all
thermal power plant A thermal power station is a type of power station in which heat energy is converted to electrical energy. In a steam-generating cycle heat is used to boil water in a large pressure vessel to produce high-pressure steam, which drives a steam ...
s – to
Carnot efficiency A Carnot cycle is an ideal thermodynamic cycle proposed by French physicist Sadi Carnot in 1824 and expanded upon by others in the 1830s and 1840s. By Carnot's theorem, it provides an upper limit on the efficiency of any classical thermodynam ...
. Due to
nuclear reprocessing Nuclear reprocessing is the chemical separation of fission products and actinides from spent nuclear fuel. Originally, reprocessing was used solely to extract plutonium for producing nuclear weapons. With commercialization of nuclear power, th ...
being standard operating procedure, a higher share of the energy contained in the original Uranium is used in France than in e.g. the United States with its once thru fuel cycle. The specific energy consumption of the trains worldwide amounts to about 150 kJ/pkm (kilojoule per passenger kilometre) and 150 kJ/tkm (kilojoule per tonne kilometre) (ca. 4.2 kWh/100 pkm and 4.2 kWh/100 tkm) in terms of final energy. Passenger transportation by rail systems requires less energy than by car or plane (one seventh of the energy needed to move a person by car in an urban context,). This is the reason why, although accounting for 9% of world passenger transportation activity (expressed in pkm) in 2015, rail passenger services represented only 1% of final energy demand in passenger transportation.


Freight

Energy consumption estimates for rail freight vary widely, and many are provided by interested parties. Some are tabulated below.


Passenger


Braking losses

Stopping is a considerable source of inefficiency. Modern electric trains like the ''
Shinkansen The , colloquially known in English as the bullet train, is a network of high-speed railway lines in Japan. Initially, it was built to connect distant Japanese regions with Tokyo, the capital, to aid economic growth and development. Beyond l ...
'' (the ''Bullet Train'') use
regenerative braking Regenerative braking is an energy recovery mechanism that slows down a moving vehicle or object by converting its kinetic energy into a form that can be either used immediately or stored until needed. In this mechanism, the electric traction mo ...
to return current into the
catenary In physics and geometry, a catenary (, ) is the curve that an idealized hanging chain or cable assumes under its own weight when supported only at its ends in a uniform gravitational field. The catenary curve has a U-like shape, superfici ...
while they brake. A Siemens study indicated that regenerative braking might recover 41.6% of the total energy consumed. The Passenger Rail (Urban and Intercity) and Scheduled Intercity and All Charter Bus Industries Technological and Operational Improvements – FINAL REPORT states that "Commuter operations can dissipate more than half of their total traction energy in braking for stops." and that "We estimate head-end power to be 35 percent (but it could possibly be as high as 45 percent) of total energy consumed by commuter railways." Having to accelerate and decelerate a heavy train load of people at every stop is inefficient despite regenerative braking which can recover typically around 20% of the energy wasted in braking. Weight is a determinant of braking losses.


Buses

* In July 2005, the average occupancy for buses in the UK was stated to be 9 passengers per vehicle. * The fleet of 244 1982
New Flyer New Flyer is a Canadian multinational bus manufacturer, specializing in the production of transit buses. New Flyer is owned by the NFI Group, a holding company for several bus manufacturers. New Flyer has several manufacturing facilities in Can ...
trolley buses in local service with
BC Transit BC Transit is a provincial crown corporation responsible for coordinating the delivery of public transportation within British Columbia, Canada, outside Greater Vancouver. BC Transit is headquartered in Victoria, British Columbia. In , the syst ...
in Vancouver, Canada, in 1994/95 used 35,454,170 kWh for 12,966,285 vehicle km, or 9.84 MJ/vehicle km. Exact ridership on trolleybuses is not known, but with all 34 seats filled this equates to 0.32 MJ/passenger km. It is quite common to see people standing on Vancouver trolleybuses. This is a service with many stops per kilometre; part of the reason for the efficiency is the use of regenerative braking. * A commuter service in
Santa Barbara, California Santa Barbara ( es, Santa Bárbara, meaning " Saint Barbara") is a coastal city in Santa Barbara County, California, of which it is also the county seat. Situated on a south-facing section of coastline, the longest such section on the West ...
, USA, found average diesel bus efficiency of (using MCI 102DL3 buses). With all 55 seats filled this equates to 330 passenger mpg; with 70% filled, 231 passenger mpg. * In 2011 the fleet of 752 buses in the city of
Lisbon Lisbon (; pt, Lisboa ) is the capital and largest city of Portugal, with an estimated population of 544,851 within its administrative limits in an area of 100.05 km2. Lisbon's urban area extends beyond the city's administrative limits w ...
had an average speed of 14.4 km/h and an average occupancy of 20.1 passengers per vehicle. * Battery electric buses combine the electric motive power of a trolleybus, the drawbacks of battery manufacture, weight and lifespan with the routing flexibility of a bus with any onboard power. Major manufacturers include BYD and Proterra.


Other

*
NASA The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeedin ...
's
Crawler-Transporter The crawler-transporters, formally known as the Missile Crawler Transporter Facilities, are a pair of tracked vehicles used to transport spacecraft from NASA's Vehicle Assembly Building (VAB) along the Crawlerway to Launch Complex 39. They we ...
was used to haul the
Saturn V Saturn V is a retired American super heavy-lift launch vehicle developed by NASA under the Apollo program for human exploration of the Moon. The rocket was human-rated, with multistage rocket, three stages, and powered with liquid-propellant r ...
and
Space Shuttle The Space Shuttle is a retired, partially reusable low Earth orbital spacecraft system operated from 1981 to 2011 by the U.S. National Aeronautics and Space Administration (NASA) as part of the Space Shuttle program. Its official program n ...
rockets from storage to the
launch pad A launch pad is an above-ground facility from which a rocket-powered missile or space vehicle is vertically launched. The term ''launch pad'' can be used to describe just the central launch platform ( mobile launcher platform), or the entir ...
. It uses diesel and has one of the highest fuel consumption rates on record, .


Air transport means


Aircraft

A principal determinant of energy consumption in aircraft is drag, which must be in the opposite direction of motion to the craft. * Drag is proportional to the
lift Lift or LIFT may refer to: Physical devices * Elevator, or lift, a device used for raising and lowering people or goods ** Paternoster lift, a type of lift using a continuous chain of cars which do not stop ** Patient lift, or Hoyer lift, mobil ...
required for flight,Barney L. Capehart (2007). ''Encyclopedia of Energy Engineering and Technology'', Volume 1. CRC Press. , . which is equal to the weight of the aircraft. As induced drag increases with weight, mass reduction, with improvements in engine efficiency and reductions in
aerodynamic drag In fluid dynamics, drag (sometimes called air resistance, a type of friction, or fluid resistance, another type of friction or fluid friction) is a force acting opposite to the relative motion of any object moving with respect to a surrounding ...
, has been a principal source of efficiency gains in aircraft, with a rule-of-thumb being that a 1% weight reduction corresponds to around a 0.75% reduction in fuel consumption. * Flight altitude affects engine efficiency. Jet-engine efficiency increases at altitude up to the tropopause, the temperature minimum of the atmosphere; at lower temperatures, the
Carnot efficiency A Carnot cycle is an ideal thermodynamic cycle proposed by French physicist Sadi Carnot in 1824 and expanded upon by others in the 1830s and 1840s. By Carnot's theorem, it provides an upper limit on the efficiency of any classical thermodynam ...
is higher. Jet engine efficiency is also increased at high speeds, but above about Mach 0.85 the airframe aerodynamic losses increase faster. * Compressibility effects: beginning at
transonic Transonic (or transsonic) flow is air flowing around an object at a speed that generates regions of both subsonic and supersonic airflow around that object. The exact range of speeds depends on the object's critical Mach number, but transoni ...
speeds of around Mach 0.85, shockwaves form increasing drag. * For supersonic flight, it is difficult to achieve a lift to drag ratio greater than 5, and fuel consumption is increased in proportion. However, the faster speed inherent to supersonic flight means that the higher fuel burn is counterbalanced by a shorter flight duration. Passenger airplanes averaged 4.8 L/100 km per passenger (1.4 MJ/passenger-km) (49 passenger-miles per gallon) in 1998. On average 20% of seats are left unoccupied. Jet aircraft efficiencies are improving: Between 1960 and 2000 there was a 55% overall fuel efficiency gain (if one were to exclude the inefficient and limited fleet of the DH Comet 4 and to consider the Boeing 707 as the base case). Most of the improvements in efficiency were gained in the first decade when jet craft first came into widespread commercial use. Compared to advanced piston engine airliners of the 1950s, current jet airliners are only marginally more efficient per passenger-mile. Between 1971 and 1998 the fleet-average annual improvement per available seat-kilometre was estimated at 2.4%.
Concorde The Aérospatiale/BAC Concorde () is a retired Franco-British supersonic airliner jointly developed and manufactured by Sud Aviation (later Aérospatiale) and the British Aircraft Corporation (BAC). Studies started in 1954, and France an ...
the
supersonic transport A supersonic transport (SST) or a supersonic airliner is a civilian supersonic aircraft designed to transport passengers at speeds greater than the speed of sound. To date, the only SSTs to see regular service have been Concorde and the Tupol ...
managed about 17 passenger-miles to the Imperial gallon; similar to a business jet, but much worse than a subsonic turbofan aircraft.
Airbus Airbus SE (; ; ; ) is a European multinational aerospace corporation. Airbus designs, manufactures and sells civil and military aerospace products worldwide and manufactures aircraft throughout the world. The company has three divisions: '' ...
puts the fuel rate consumption of their
A380 The Airbus A380 is a large wide-body airliner that was developed and produced by Airbus. It is the world's largest passenger airliner and only full-length double-deck jet airliner. Airbus studies started in 1988, and the project was annou ...
at less than 3 L/100 km per passenger (78 passenger-miles per US gallon). The mass of an aircraft can be reduced by using light-weight materials such as
titanium Titanium is a chemical element with the symbol Ti and atomic number 22. Found in nature only as an oxide, it can be reduced to produce a lustrous transition metal with a silver color, low density, and high strength, resistant to corrosion i ...
,
carbon fibre Carbon fiber-reinforced polymers (American English), carbon-fibre-reinforced polymers (Commonwealth English), carbon-fiber-reinforced plastics, carbon-fiber reinforced-thermoplastic (CFRP, CRP, CFRTP), also known as carbon fiber, carbon compo ...
and other composite plastics. Expensive materials may be used, if the reduction of mass justifies the price of materials through improved fuel efficiency. The improvements achieved in fuel efficiency by mass reduction, reduces the amount of fuel that needs to be carried. This further reduces the mass of the aircraft and therefore enables further gains in fuel efficiency. For example, the Airbus A380 design includes multiple light-weight materials. Airbus has showcased
wingtip device Wingtip devices are intended to improve the efficiency of fixed-wing aircraft by reducing drag (physics), drag. Although there are several types of wing tip devices which function in different manners, their intended effect is always to redu ...
s (sharklets or winglets) that can achieve 3.5 percent reduction in fuel consumption. There are wingtip devices on the Airbus A380. Further developed Minix winglets have been said to offer 6 percent reduction in fuel consumption. Winglets at the tip of an aircraft wing smooth out the wing-tip vortex (reducing the aircraft's wing drag) and can be retrofitted to any airplane. NASA and Boeing are conducting tests on a " blended wing" aircraft. This design allows for greater fuel efficiency since the whole craft produces lift, not just the wings. The blended wing body (BWB) concept offers advantages in structural, aerodynamic and operating efficiencies over today's more conventional fuselage-and-wing designs. These features translate into greater range, fuel economy, reliability and life cycle savings, as well as lower manufacturing costs. NASA has created a cruise efficient STOL (CESTOL) concept. Fraunhofer Institute for Manufacturing Engineering and Applied Materials Research (IFAM) have researched a
shark Sharks are a group of elasmobranch fish characterized by a cartilaginous skeleton, five to seven gill slits on the sides of the head, and pectoral fins that are not fused to the head. Modern sharks are classified within the clade Selachi ...
skin imitating paint that would reduce drag through a riblet effect. Aircraft are a major potential application for new technologies such as aluminium
metal foam Regular foamed aluminium A metal foam is a cellular structure consisting of a solid metal (frequently aluminium) with gas-filled pores comprising a large portion of the volume. The pores can be sealed (closed-cell foam) or interconnected (open- ...
and
nanotechnology Nanotechnology, also shortened to nanotech, is the use of matter on an atomic, molecular, and supramolecular scale for industrial purposes. The earliest, widespread description of nanotechnology referred to the particular technological goal ...
such as the shark skin imitating paint.
Propeller A propeller (colloquially often called a screw if on a ship or an airscrew if on an aircraft) is a device with a rotating hub and radiating blades that are set at a pitch to form a helical spiral which, when rotated, exerts linear thrust upon ...
systems, such as
turboprop A turboprop is a turbine engine that drives an aircraft propeller. A turboprop consists of an intake, reduction gearbox, compressor, combustor, turbine, and a propelling nozzle. Air enters the intake and is compressed by the compressor. ...
s and propfans are a more fuel efficient technology than jets. But turboprops have an optimum speed below about 450 mph (700 km/h). This speed is less than used with jets by major airlines today. With the current high price for
jet fuel Jet fuel or aviation turbine fuel (ATF, also abbreviated avtur) is a type of aviation fuel designed for use in aircraft powered by gas-turbine engines. It is colorless to straw-colored in appearance. The most commonly used fuels for commercial a ...
and the emphasis on engine/airframe efficiency to reduce emissions, there is renewed interest in the propfan concept for jetliners that might come into service beyond the
Boeing 787 The Boeing 787 Dreamliner is an American wide-body jet airliner developed and manufactured by Boeing Commercial Airplanes. After dropping its unconventional Sonic Cruiser project, Boeing announced the conventional 7E7 on January 29, 2003, ...
and Airbus A350XWB. For instance, Airbus has patented aircraft designs with twin rear-mounted counter-rotating propfans. NASA has conducted an Advanced Turboprop Project (ATP), where they researched a variable pitch propfan that produced less noise and achieved high speeds. Related to fuel efficiency is the impact of aviation emissions on climate.


Small aircraft

* Motor-gliders can reach an extremely low fuel consumption for cross-country flights, if favourable thermal air currents and winds are present. * At 160 km/h, a diesel powered two-seater Dieselis burns 6 litres of fuel per hour, 1.9 litres per 100 passenger km. * at 220 km/h, a four-seater 100 hp MCR-4S burns 20 litres of gas per hour, 2.2 litres per 100 passenger km. * Under continuous motorised flight at 225 km/h, a Pipistrel Sinus burns 11 litres of fuel per flight hour. Carrying 2 people aboard, it operates at 2.4 litres per 100 passenger km. * Ultralight aircraft Tecnam P92 Echo Classic at cruise speed of 185 km/h burns 17 litres of fuel per flight hour, 4.6 litres per 100 passenger km (2 people). Other modern ultralight aircraft have increased efficiency; Tecnam P2002 Sierra RG at cruise speed of 237 km/h burns 17 litres of fuel per flight hour, 3.6 litres per 100 passenger km (2 people). * Two-seater and four-seater flying at 250 km/h with old generation engines can burn 25 to 40 litres per flight hour, 3 to 5 litres per 100 passenger km. * The
Sikorsky S-76 The Sikorsky S-76 is a medium-size commercial utility helicopter designed and produced by the American helicopter manufacturer Sikorsky Aircraft. It is the company's first helicopter specifically developed for the civilian market. The S-76 ...
C++ twin turbine helicopter gets about at and carries 12 for about 19.8 passenger-miles per gallon (11.9 L per 100 passenger km).


Water transport means


Ships


Queen Elizabeth

Cunard Cunard () is a British shipping and cruise line based at Carnival House at Southampton, England, operated by Carnival UK and owned by Carnival Corporation & plc. Since 2011, Cunard and its three ships have been registered in Hamilton, Ber ...
stated that Queen Elizabeth 2 travelled 49.5 feet per imperial gallon of diesel oil (3.32 m/L or 41.2 ft/US gal), and that it had a passenger capacity of 1777. Thus carrying 1777 passengers we can calculate an efficiency of 16.7 passenger miles per imperial gallon (16.9 L/100 p·km or 13.9 p·mpg–US).


Cruise ships

has a capacity of 6,296 passengers and a fuel efficiency of 14.4 passenger miles per US gallon.
Voyager-class cruise ship The ''Voyager'' class refers to a design of post-Panamax cruise ships owned and operated by Royal Caribbean International. The ''Voyager''-class ships were built at Kværner Masa-Yards Turku New Shipyard, Finland. There are two generations of '' ...
s have a capacity of 3,114 passengers and a fuel efficiency of 12.8 passenger miles per US gallon.


Emma Maersk

Emma Maersk uses a Wärtsilä-Sulzer RTA96-C, which consumes 163 g/kW·h and 13,000 kg/h. If it carries 13,000 containers then 1 kg fuel transports one container for one hour over a distance of 45 km. The ship takes 18 days from Tanjung (Singapore) to Rotterdam (Netherlands), 11 from Tanjung to Suez, and 7 from Suez to Rotterdam, which is roughly 430 hours, and has 80 MW, +30 MW. 18 days at a mean speed of gives a total distance of . Assuming the Emma Maersk consumes diesel (as opposed to fuel oil which would be the more precise fuel) then 1 kg diesel = 1.202 litres = 0.317 US gallons. This corresponds to 46,525 kJ. Assuming a standard 14 tonnes per container (per teu) this yields 74 kJ per tonne-km at a speed of 45 km/h (24 knots).


Boats

A
sailboat A sailboat or sailing boat is a boat propelled partly or entirely by sails and is smaller than a sailing ship. Distinctions in what constitutes a sailing boat and ship vary by region and maritime culture. Types Although sailboat terminology ...
, much like a solar car, can locomote without consuming any fuel. A sail boat such as a
dinghy A dinghy is a type of small boat, often carried or towed by a larger vessel for use as a tender. Utility dinghies are usually rowboats or have an outboard motor. Some are rigged for sailing but they differ from sailing dinghies, whic ...
using just wind power requires no input energy in terms of fuel. However some manual energy is required by the crew to steer the boat and adjust the sails using lines. In addition energy will be needed for demands other than propulsion, such as cooking, heating or lighting. The fuel efficiency of a single-occupancy boat is highly dependent on the size of its engine, the speed at which it travels, and its displacement. With a single passenger, the equivalent energy efficiency will be lower than in a car, train, or plane.


International transport comparisons


European Public transport

Rail and bus are generally required to serve 'off peak' and rural services, which by their nature have lower loads than city bus routes and inter city train lines. Moreover, due to their 'walk on' ticketing it is much harder to match daily demand and passenger numbers. As a consequence, the overall load factor on UK railways is 35% or 90 people per train: Conversely, airline services generally work on point-to-point networks between large population centres and are 'pre-book' in nature. Using
yield management Yield management is a variable pricing strategy, based on understanding, anticipating and influencing consumer behavior in order to maximize revenue or profits from a fixed, time-limited resource (such as airline seats or hotel room reservations ...
, overall load factors can be raised to around 70–90%. Intercity train operators have begun to use similar techniques, with loads reaching typically 71% overall for
TGV The TGV (french: Train à Grande Vitesse, "high-speed train"; previously french: TurboTrain à Grande Vitesse, label=none) is France's intercity high-speed rail service, operated by SNCF. SNCF worked on a high-speed rail network from 1966 to 19 ...
services in France and a similar figure for the UK's
Virgin Rail Group Virgin Rail Group was formed by the Virgin Group to bid for rail franchises in the United Kingdom during the privatisation of British Rail in the late 1990s. United Kingdom operations Origins Virgin bid for a number of franchises, inclu ...
services. For emissions, the electricity generating source needs to be taken into account.


US Passenger transport

The US Transport Energy Data Book states the following figures for passenger transport in 2018. These are based on actual consumption of energy, at whatever occupancy rates there were. For modes using electricity, losses during generation and distribution are included. Values are not directly comparable due to differences in types of services, routes, etc.


US Freight transport

The US Transport Energy book states the following figures for freight transport in 2010: From 1960 to 2010 the efficiency of air freight has increased 75%, mostly due to more efficient jet engines. 1 gal (3.785 L, 0.833 gal) of fuel can move a ton of cargo 857 km or 462 nmi by barge, or by rail, or by lorry. Compare: * Space Shuttle used to transport freight to the other side of the Earth (see above): 40 megajoules per tonne-kilometre. * Net energy for lifting: 10 megajoules per tonne-kilometre.


Canadian transport

Natural Resources Canada's Office of Energy Efficiency publishes annual statistics regarding the efficiency of the entire Canadian fleet. For researchers, these fuel consumption estimates are more realistic than the fuel consumption ratings of new vehicles, as they represent the real world driving conditions, including extreme weather and traffic. The annual report is called Energy Efficiency Trends Analysis. There are dozens of tables illustrating trends in energy consumption expressed in energy per passenger km (passengers) or energy per tonne km (freight).


French environmental calculator

The environmental calculator of the French environment and energy agency (ADEME) published in 2007 using data from 2005 enables one to compare the different means of transport as regards the emissions (in terms of
carbon dioxide equivalent Global warming potential (GWP) is the heat absorbed by any greenhouse gas in the atmosphere, as a multiple of the heat that would be absorbed by the same mass of carbon dioxide (). GWP is 1 for . For other gases it depends on the gas and the tim ...
) as well as the consumption of
primary energy Primary energy (PE) is an energy form found in nature that has not been subjected to any human engineered conversion process. It is energy contained in raw fuels, and other forms of energy, including waste, received as input to a system. Prim ...
. In the case of an electric vehicle, the ADEME makes the assumption that 2.58  toe as primary energy are necessary for producing one toe of electricity as end energy in France (see Embodied energy: In the energy field). This computer tool devised by the ADEME shows the importance of public transport from an environmental point of view. It highlights the primary energy consumption as well as the emissions due to transport. Due to the relatively low environmental impact of
radioactive waste Radioactive waste is a type of hazardous waste that contains radioactive material. Radioactive waste is a result of many activities, including nuclear medicine, nuclear research, nuclear power generation, rare-earth mining, and nuclear weapon ...
, compared to that of fossil fuel combustion emissions, this is not a factor in the tool. Moreover,
intermodal passenger transport Intermodal passenger transport, also called mixed-mode commuting, involves using two or more modes of transportation in a journey. Mixed-mode commuting is often used to combine the strengths (and offset the weaknesses) of various transportati ...
is probably a key to
sustainable transport Sustainable transport refers to ways of transportation that are sustainable in terms of their social and environmental impacts. Components for evaluating sustainability include the particular vehicles used for road, water or air transport; th ...
, by allowing people to use less polluting means of transport.


German environmental costs

Deutsche Bahn The (; abbreviated as DB or DB AG) is the national railway company of Germany. Headquartered in the Bahntower in Berlin, it is a joint-stock company ( AG). The Federal Republic of Germany is its single shareholder. describes itself as the ...
calculates the energy consumption of their various means of transportation.


Note - External costs not included above

To include ''all'' the energy used in transport, we would need to also include the external energy costs of producing, transporting and packaging of fuel (food or fossil fuel or electricity), the energy incurred in disposing of exhaust waste, and the energy costs of manufacturing the vehicle. For example, a human walking requires little or no special equipment while automobiles require a great deal of energy to produce and have relatively short product lifespans. However, these external costs are independent of the energy cost per distance travelled, and can vary greatly for a particular vehicle depending on its lifetime, how often it is used and how it is energized over its lifetime. Thus this article's numbers include none of these external factors.


See also

*
ACEA agreement The ACEA agreement refers to a voluntary agreement between the European Automobile Manufacturers Association (ACEA) and the European Commission to limit the amount of carbon dioxide (CO2) emitted by passenger cars sold in Europe. Signed in 1998, ...
*
Alternative fuel vehicle An alternative fuel vehicle is a motor vehicle that runs on alternative fuel rather than traditional petroleum fuels (petrol or petrodiesel). The term also refers to any technology (e.g. electric car, hybrid electric vehicles, solar-powered ve ...
* Brake-specific fuel consumption * Corporate average fuel economy (CAFE) *
Emission standard Emission standards are the legal requirements governing air pollutants released into the atmosphere. Emission standards set quantitative limits on the permissible amount of specific air pollutants that may be released from specific sources over ...
*
Fuel economy in automobiles The fuel economy of an automobile relates distance traveled by a vehicle and the amount of fuel consumed. Consumption can be expressed in terms of volume of fuel to travel a distance, or the distance traveled per unit volume of fuel consumed. S ...
* Fuel-management systems * Gas-guzzler *
Gasoline gallon equivalent Gasoline gallon equivalent (GGE) or gasoline-equivalent gallon (GEG) is the amount of an alternative fuel it takes to equal the energy content of one liquid gallon of gasoline. GGE allows consumers to compare the energy content of competing fue ...
*
Life-cycle assessment Life cycle assessment or LCA (also known as life cycle analysis) is a methodology for assessing environmental impacts associated with all the stages of the life cycle of a commercial product, process, or service. For instance, in the case ...
* Marine fuel management * Thrust-specific fuel consumption *
Vehicular metrics There are a broad range of metrics that denote the relative capabilities of various vehicle A vehicle (from la, vehiculum) is a machine that transports people or cargo. Vehicles include wagons, bicycles, motor vehicles (motorcycles, car ...
*
Transport Transport (in British English), or transportation (in American English), is the intentional movement of humans, animals, and goods from one location to another. Modes of transport include air, land ( rail and road), water, cable, pipelin ...
* Speed record


Footnotes

{{reflist, colwidth=30em


External links


ECCM Study for rail, road and air journeys between main UK cities

Traction Summary Report 2007– Prof. Roger Kemp

Transport Energy Data Book
(US)
Fuel Consumption Ratings

Infographic on Energy Efficiency in Transportation
Webarchive template wayback links Energy conservation Fuels Energy use comparisons