The "New Advanced Vehicle with Intelligence 5-speed" (NAVi5, also sometimes written "NAVI5" or "NAVI-5") was an

automated manual transmission The automated manual transmission (AMT) is a type of transmission (mechanics), transmission for motor vehicles. It is essentially a conventional manual transmission equipped with automatic actuation to operate the clutch and/or shift Gear train ...

developed by

Isuzu , commonly known as Isuzu (, ), is a Japanese multinational automobile manufacturer headquartered in Yokohama, Kanagawa Prefecture. Its principal activity is the production, marketing and sale of Isuzu commercial vehicles and diesel engines ...

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

, and introduced in August 1984. It was initially developed for use in

trucks A truck or lorry is a motor vehicle designed to transport freight, carry specialized payloads, or perform other utilitarian work. Trucks vary greatly in size, power, and configuration, but the vast majority feature body-on-frame construction ...

, but was first made available in Isuzu's Aska sedan and subsequently the Gemini and their other Japanese domestic market vehicles. It preceded the likes of

Alfa Romeo Alfa Romeo Automobiles S.p.A. () is an Italian carmaker known for its sports-oriented vehicles, strong auto racing heritage, and iconic design. Headquartered in Turin, Italy, it is a subsidiary of Stellantis Europe and one of 14 brands of mu ...

’s ''

Selespeed Selespeed is the name of an electrohydraulic manual transmission, automated manual transmission used in Alfa Romeo cars, developed by Italian company Magneti Marelli and made by Graziano Trasmissioni. The Selespeed is an automated manual gearbox w ...

'' and

Opel Opel Automobile GmbH (), usually shortened to Opel, is a German automobile manufacturer which has been a subsidiary of Stellantis since 16 January 2021. It was owned by the American automaker General Motors from 1929 until 2017 and the PSA Gr ...

’s '' Easytronic'' by more than a decade. It was superseded by the Smoother transmission in newer trucks.

Models

The NAVi5 was used in the following Isuzu vehicles: Isuzu added the NAVi6, a six-speed version, to the following trucks:

Features

Unlike "traditional" automatic gearboxes with a

torque converter A torque converter is a device, usually implemented as a type of fluid coupling, that transfers rotating power from a prime mover, like an internal combustion engine, to a rotating driven load. In a vehicle with an automatic transmission, the ...

and planetary gears, the mechanical aspects of the NAVi5 are identical to those of a conventional five-speed

manual transmission A manual transmission (MT), also known as manual gearbox, standard transmission (in Canadian English, Canada, British English, the United Kingdom and American English, the United States), or stick shift (in the United States), is a multi-speed ...

with a dry-clutch. The shifting and clutch operations though, are done automatically by two

hydraulic actuator A hydraulic cylinder (also called a linear hydraulic motor) is a mechanical actuator that is used to give a unidirectional force through a unidirectional stroke. It has many applications, notably in construction equipment ( engineering vehicles ...

s connected to an electronic

computer A computer is a machine that can be Computer programming, programmed to automatically Execution (computing), carry out sequences of arithmetic or logical operations (''computation''). Modern digital electronic computers can perform generic set ...

(an 8-bit unit with 8 KB ROM and 192 KB RAM). The early version of the NAVi5 only had an automatic mode with an ability to lock out certain gears, thus operating in a manner similar to a traditional automatic. The later version added a manual mode, enabling the driver to select specific gears. The NAVi5 also came with autocruise and Hill-Start Aid as standard features. A Japanese television commercial for the Aska heralded NAVi5 as “Not a manual, not a torque converter.”

Reception

The customer reactions toward the NAVi5 were mixed. Some liked the more “direct” feel and better fuel economy it offered compared to those of typical automatic gearboxes. Others, however, were turned off by what they felt as awkward shifting program and the acceleration gap during shifting. The NAVi5 also required gentle throttle operations when accelerating from standstill since it didn't offer creep function. It was outsold by the conventional manual and automatic gearboxes in both the Aska and Gemini and subsequently dropped in the next generation Gemini. (Isuzu stopped manufacturing the Aska in-house after the first generation.)

References

{{Powertrain 1984 introductions 1984 establishments in Japan NAVi5 Automotive technology tradenames Automobile transmissions Automotive transmission technologies