Toyota G engine
The Toyota Motor Corporation G-family engine is a family of straight-6 piston engines produced from 1979 to 2008. It is notable in that only a single displacement, , was produced in this series. Initially belt-driven OHC non-interference engines (except the VVT-i version which is an interference engine), multivalve DOHC (except the 1G-EU SOHC 12 valve engine) and variable valve timing were added later during the production run. The 1G-GEU was Toyota's first mass produced four-valve twincam engine. A prototype version of the 1G-GEU called the LASREα–X, featuring twin-turbos, variable valve timing and intake as well as variable displacement, was fitted to the Toyota FX-1 show car at the 1983 Tokyo Motor Show. It showcased a number of technologies which were later to become commonplace. These engines were used as a lower-displacement alternative to the more upmarket M family and JZ family straight-sixes. For ten months (in 1967-1968), Toyota also offered Hino's GR100 engine as the "Toyota G" in the shortlived Briska light truck. G (Hino GR100)
After Toyota's takeover of Hino Motors in 1967, the Briska one-tonne truck was sold with Toyota badging for ten months. The engine code was changed from Hino's "GR100" to "G" for these cars. The engine is a 1251 cc watercooled OHV inline-four with distant Renault origins and was originally developed by Hino for their Contessa passenger car. Bore and stroke are , maximum power  at 5500 rpm. Hino's earlier models had a variety of power outputs ranging from 52 to 65 PS. Apart from its name, this engine is unrelated to the later series of Toyota G engines. 1G
Since just one displacement was offered, all G-family engines are marked 1G and share the same "square"  bore and stroke. Applications:
 Toyota Soarer
 Toyota Celica Supra
 Toyota Crown
 Toyota Crown Comfort/Crown Sedan
 Toyota Cressida/Mark II/Cresta/Chaser
 Toyota Altezza
 Lexus IS200

1G-E
The export-spec two-valve 1G-E had no emissions controls and were used in commercial vehicles and for a few export markets, mostly southeast Asia. Typical specifications:
  at 5000 rpm,  torque at 4000 rpm (Mark II, 1986, Indonesia)
  at 5200 rpm, JDM Crown GS130/131/136V/130G

1G-EU
The Japan-spec 1G-EU was produced from 1979 through 1988. This and the 1G-E are the only two-valve SOHC members of the family. Output was  at 5400 rpm and  at 4400 rpm. 1G-FE

The DOHC 1G-FE uses a narrow valve angle and other fuel economy optimizations. It was introduced in 1988, it features a cast iron block with aluminum cylinder head and uses the slave cam system. Output was  at 5,600 rpm and  at 4,400 rpm. In 1998 VVT-i was added, which bumped output to  at 6,200 rpm and  at 4,400 rpm for the Altezza/IS 200. Production of this engine family ceased in 2008 after the discontinuation of the Crown Sedan mild hybrid. Applications:
 Toyota Altezza/Lexus IS 200
 Toyota Crown
 Aug 2001–Aug 2008 Toyota Crown Sedan GBS12, GXS12
 Toyota Chaser/Mark II/Cresta
 Toyota Mark II Blit
 Toyota Verossa
 Toyota Supra (A70) GA70 "G" grade
 Toyota Soarer

1G-GEU

The 24-valve DOHC 1G-GEU was intended for high performance and featured a pent-roof combustion chamber. Introduced in August 1982 and produced through 1986, mostly for the Japanese market, it was Toyota's first multi-valve twincam engine to make it to the market, and won the "JSME Medal for New Technology" (Japan Society of Mechanical Engineers) in 1982. Output was  at 6,200 rpm and  at 5,600 rpm. To minimize the downsides of a multi-valve setup, the 1G-GEU was also equipped with T-VIS (Toyota Variable Induction System), increasing low to mid-engine speed torque. Like all following twin cam Toyotas, it used a timing belt rather than chain, for less noise and lower maintenance requirements. In August 1983, the fuel injection system was changed to EFI-D, which measures the pressure in the intake manifold to determine the proper air-fuel mixture. Applications:
 Aug 1982–1985 Celica XX GA61
 Aug 1982–1992 Toyota Chaser/Mark II/Cresta
 Aug 1983–1995 Toyota Crown
 Feb 1983–1991 Toyota Soarer

1G-GE
The 1G-GE replaced the 1G-GEU in 1988. It was detuned from  to  and served the same cars as 1G-GEU did. Torque was  at 5600 rpm. It was produced for the Supra GA70 until 1993. 1G-GTE

The 24-valve DOHC 1G-GTE added two CT-12 turbochargers to the versatile motor. There were 3 generations of this engine both air-to-air and air-to-water intercoolers were used, pushing output from  at 6200 rpm and  at 3800 rpm using the air-to-air over the air-to-water. This was the most powerful engine of the whole G family. In May 1991 it was replaced with the 280 PS 1JZ-GTE on most Toyota cars. Applications:
 1986–1992 Supra MK3 (GA70; JDM only)
 1986–1992 Mark II/Chaser/Cresta (GX71, GX81)
 1986–1991 Soarer (GZ20)

1G-GP/GPE
The 1G-GP and 1G-GPE was an LPG version of the 1G-GE engine. Output is  at 5600 rpm and torque is  at 2400 rpm. Applications:
 Toyota Crown Sedan (GS130, GS151)
 Toyota Crown Comfort/Sedan (GXS10)

1G-GZE
The  1G-GZE was a supercharged version produced from 1986 until 1992. Output is  at 6,000 rpm and   at 3,600 rpm. Like the turbo, it was a 24-valve DOHC 6-cylinder engine but featured a distributorless ignition system (DIS). The 1G-GZE was mated only with automatic gearboxes. In August 1991 it was replaced with the 1JZ-GE on the Mark II/Chaser/Cresta, while serving on the Crown until 1992. Applications:
 Toyota Crown GS120, GS121, GS131, GS130G (Station Wagon)
 1988–1990 Toyota Mark II/Chaser/Cresta GX81

References

See also

 List of Toyota engines

G
Straight-six engines
Gasoline engines by model