The High Value engine family from
General Motors
General Motors Company (GM) is an American Multinational corporation, multinational Automotive industry, automotive manufacturing company headquartered in Detroit, Michigan, United States. The company is most known for owning and manufacturing f ...
is a group of
cam-in-block A cam-in-block engine is where the camshaft is located in the engine block
In an internal combustion engine, the engine block is the structure that contains the cylinders and other components. The engine block in an early automotive engine con ...
or
overhead valve
An overhead valve engine, abbreviated (OHV) and sometimes called a pushrod engine, is a piston engine whose valves are located in the cylinder head above the combustion chamber. This contrasts with flathead (or "sidevalve") engines, where the v ...
V6 engine
A V6 engine is a six- cylinder piston engine where the cylinders and cylinder blocks share a common crankshaft and are arranged in a V configuration.
The first V6 engines were designed and produced independently by Marmon Motor Car Company, ...
s. These engines feature cast iron blocks and aluminum heads, and use the same 60° vee bank as the
60° V6 family they are based on, but the new bore required offsetting the bores by away from the engine center line. These engines (aside from the LX9) are the first cam-in-block engines to implement
variable valve timing
Variable valve timing (VVT) is the process of altering the timing of a Poppet valve, valve lift event in an internal combustion engine, and is often used to improve performance, fuel economy or emissions. It is increasingly being used in combina ...
, and won the 2006 Breakthrough Award from ''
Popular Mechanics
''Popular Mechanics'' (often abbreviated as ''PM'' or ''PopMech'') is a magazine of popular science and technology, featuring automotive, home, outdoor, electronics, science, do it yourself, and technology topics. Military topics, aviation an ...
'' for this innovation. For the 2007
model year
The model year (sometimes abbreviated as MY) is a method of describing the version of a product which has been produced over multiple years. The model year may or may not be the same as the calendar year in which the product was manufactured.
...
, the 3900 engine featured optional
displacement on demand or "Active Fuel Management" which deactivates a bank of cylinders under light load to increase highway fuel economy. It was rumored that GM would produce a 3-valve design, but that never came to be. These engines were produced primarily at the GM factory in
Tonawanda, New York, and at the
Ramos Arizpe engine plant in Mexico. The assembly line for this engine was manufactured by Hirata Corporation at its powertrain facility in
Kumamoto, Japan.
As of the 2012 model year, GM no longer sells these engines in any
U.S. market vehicles.
3.5
:''These engines should not be confused with the 3.5L
DOHC
An overhead camshaft (OHC) engine is a piston engine in which the camshaft is located in the cylinder head above the combustion chamber. This contrasts with earlier overhead valve engines (OHV), where the camshaft is located below the combus ...
LX5 (Shortstar) V6 engine.''
LX9
The LX9 3500 is an OHV engine based on the
3400 V6. Bore and stroke are , for a displacement of . According to a GM press release from October 2002, the 3500 V6 offered improved performance and fuel efficiency, as well as reduced emissions and
NVH compared to the 3400 V6. The 3500 V6 featured an updated
powertrain control module
A power-train control module, abbreviated PCM, is an automotive industry, automotive component, a control unit, used on motor vehicles. It is generally a combined controller consisting of the engine control unit (ECU) and the transmission contro ...
, electronic throttle control, fuel injection system,
exhaust manifold,
catalytic converter
A catalytic converter part is an vehicle emissions control, exhaust emission control device which converts toxic gases and pollutants in exhaust gas from an internal combustion engine into less-toxic pollutants by catalysis, catalyzing a redox ...
, accessory drive system, and improved cooling and sealing systems. Power output ranges from to , and torque ranges from to .
Applications:
* 2005–2006
Buick Terraza/
Chevrolet Uplander/
Pontiac Montana SV6/
Saturn Relay
* 2004–2006
Chevrolet Malibu
The Chevrolet Malibu is a mid-size car that was manufactured and marketed by Chevrolet from 1964 to 1983 and from 1997 to 2025. The Malibu began as a trim-level of the Chevrolet Chevelle, becoming its own model line in 1978. Originally a rear-w ...
/
Chevrolet Malibu Maxx
* 2005–2006
Pontiac G6 Sedan / Coupe
* 2006–2007
Buick Rendezvous
* 2006
Pontiac G6 GT Convertible
LZ4

The LZ4 3500 is an OHV engine that uses a block similar to the 3.9L ''
LZ9'' V6. It was introduced for the 2006 model year Impala and Monte Carlo. Bore is the same , but the stroke is reduced to for a displacement of . It includes continuously variable cam timing (fixed overlap). Output is at 5800 rpm and at 4000 rpm. Horsepower rating changed for the 2007 model year to at 5800 rpm and torque at 4000 rpm. The Chevrolet Malibu, Pontiac G6, and Saturn Aura came equipped with this engine for 2007 (previously, the Malibu and G6 had the non-VVT 3.5 L ''
LX9''). In 2008, the SAE horsepower rating was dropped to , keeping torque as is. On Pontiac G6 convertible models, horsepower was rated at .
Applications:
* 2006–2009
Chevrolet Impala
The Chevrolet Impala () is a full-size car that was built by Chevrolet for model years 1958 to 1985, 1994 to 1996, and 2000 to 2020. The Impala was Chevrolet's popular flagship passenger car and was among the better-selling American-made auto ...
* 2006–2007
Chevrolet Monte Carlo
* 2008–2010
Chevrolet Malibu
The Chevrolet Malibu is a mid-size car that was manufactured and marketed by Chevrolet from 1964 to 1983 and from 1997 to 2025. The Malibu began as a trim-level of the Chevrolet Chevelle, becoming its own model line in 1978. Originally a rear-w ...
Fleet
* 2007
Chevrolet Malibu
The Chevrolet Malibu is a mid-size car that was manufactured and marketed by Chevrolet from 1964 to 1983 and from 1997 to 2025. The Malibu began as a trim-level of the Chevrolet Chevelle, becoming its own model line in 1978. Originally a rear-w ...
Sedan/ Maxx
* 2007–2009
Saturn Aura
* 2007–2010
Pontiac G6
* 2008–2010
Saturn Vue
The Saturn Vue is a compact SUV that was built and marketed by Saturn, and it was Saturn's best-selling model. It was the first vehicle to use the GM Theta platform when it was introduced in 2001 for the 2002 model year. The Vue was facelifte ...
XE AWD LZ4 (Note: Only vehicle to have used the GM METRIC bellhousing for 6T70)
Note: GM often refers to this engine in its literature as a "3.5L V6 with Variable Valve Timing."
LZE
The LZE 3500 is an OHV
flexible-fuel engine based on the 3.5L ''
LZ4'' V6 (it can use either plain gasoline or
E85) and includes continuously
variable cam timing
Variable camshaft timing (VCT) is an Car, automobile variable valve timing technology developed by Ford Motor Company, Ford. It allows for more optimum engine performance, reduced emissions, and increased fuel efficiency compared to engines with f ...
(fixed overlap). Bore and stroke are , for a displacement of . Output is at 5800 rpm and at 4000 rpm.
Applications:
* 2006–2011
Chevrolet Impala
The Chevrolet Impala () is a full-size car that was built by Chevrolet for model years 1958 to 1985, 1994 to 1996, and 2000 to 2020. The Impala was Chevrolet's popular flagship passenger car and was among the better-selling American-made auto ...
* 2006–2007
Chevrolet Monte Carlo
3.9
Bore and stroke are for a displacement of .
LZ9
The LZ9 3900 has roller rocker arms, a
variable length intake manifold, and
Variable Cam Timing
Variable camshaft timing (VCT) is an Car, automobile variable valve timing technology developed by Ford Motor Company, Ford. It allows for more optimum engine performance, reduced emissions, and increased fuel efficiency compared to engines with f ...
, a novelty on a pushrod engine. A computer-controlled plenum divider, along with the VVT cam function, improves efficiency across a broader RPM range.
It produces up to and of torque, with a wide
torque curve
In physics and mechanics, torque is the rotational analogue of linear force. It is also referred to as the moment of force (also abbreviated to moment). The symbol for torque is typically \boldsymbol\tau, the lowercase Greek alphabet, Greek let ...
. At least 90% of the maximum torque output is available from 1500 rpm to 5500 rpm.
Applications:
* 2006
Pontiac G6 GTP Sedan / Coupe / Convertible
* 2007
Pontiac G6 GT Sport Package Sedan / Coupe
* 2007–2009
Pontiac G6 GT Sport Package Convertible
* 2006–2007
Chevrolet Malibu SS
* 2006
Chevrolet Impala
The Chevrolet Impala () is a full-size car that was built by Chevrolet for model years 1958 to 1985, 1994 to 1996, and 2000 to 2020. The Impala was Chevrolet's popular flagship passenger car and was among the better-selling American-made auto ...
/
Monte Carlo
Monte Carlo ( ; ; or colloquially ; , ; ) is an official administrative area of Monaco, specifically the Ward (country subdivision), ward of Monte Carlo/Spélugues, where the Monte Carlo Casino is located. Informally, the name also refers to ...
(/)
* 2006–2009
Buick Terraza/
Chevrolet Uplander/
Pontiac Montana SV6/
Saturn Relay
* 2009–2011
Buick Lucerne ( ( in
California-emissions states))
LGD
The LGD 3900 is a
flexible-fuel version of the LZ9, and like its 3.5L
LZE counterpart, it can run on
E85, pure gasoline, or any mixture of the two. This is the last version of the 3900 V6. The LGD was not available with Active Fuel Management. Output is slightly reduced at 230 horsepower at 5700 rpm and 235 lb-ft of torque at 3200 rpm.
Applications:
* 2007–2009
Buick Terraza/
Chevrolet Uplander/
Pontiac Montana SV6
* 2009–2011
Buick Lucerne/
Chevrolet Impala
The Chevrolet Impala () is a full-size car that was built by Chevrolet for model years 1958 to 1985, 1994 to 1996, and 2000 to 2020. The Impala was Chevrolet's popular flagship passenger car and was among the better-selling American-made auto ...
* 2007
Saturn Relay ''(fleet only)''
LZ8 and LZG
The LZ8 3900 has the same
Variable Cam Timing
Variable camshaft timing (VCT) is an Car, automobile variable valve timing technology developed by Ford Motor Company, Ford. It allows for more optimum engine performance, reduced emissions, and increased fuel efficiency compared to engines with f ...
technology as the LZ9. The 2007 model year introduces the
Active Fuel Management
Active Fuel Management (formerly known as displacement on demand (DoD)) is a trademarked name for the automobile variable displacement technology from General Motors. It allows a V6 or V8 engine to "turn off" half of the cylinders under light-l ...
system (formerly known as
Displacement on Demand), which can turn off a bank of cylinders under a light load for increased fuel economy. Output is slightly lower than the LZ9 at and . For 2008, it was replaced by the LZG 3900, a
flexible-fuel version of the LZ8.
Applications:
* 2007
Chevrolet Impala
The Chevrolet Impala () is a full-size car that was built by Chevrolet for model years 1958 to 1985, 1994 to 1996, and 2000 to 2020. The Impala was Chevrolet's popular flagship passenger car and was among the better-selling American-made auto ...
(LZ8)
* 2008 Chevrolet Impala (LZG)
The LZ8 was replaced by the LGD for 2009.
References
External links
GM Powertrain website
{{GM late engine timeline
High Value
V6 engines
Gasoline engines by model