Infiniti G Line
The Infiniti G Line is a series of compact executive cars manufactured and marketed by Infiniti, a luxury division of Nissan, for the 1991–1996 and 1999–2016 model years — across four generations.
The first two generations of the Infiniti G were sedans based on the Nissan Primera. Beginning with its third generation, the Infiniti G have been rebadged versions of the Nissan Skyline line of sedans and coupes that were exported to the United States and Canada. The fourth generation introduced the hardtop coupe convertible. The Nissan FM platform, used with the third and fourth generations of the Infiniti G, also underpins the Nissan 370Z and has shared components with the Infiniti M, Infiniti EX, and Infiniti FX.
Infiniti established a new naming convention beginning with the 2014 model year; all passenger cars are designated by the letter "Q," while sport-utility model names begin with "QX." The Infiniti G was to have been replaced by the Infiniti Q50, but the G37 was revived as the Q40 beginning with the 2015 model year.
First generation (P10; 1990)
The Infiniti G20 was Infiniti's entry-level luxury car in the United States from 1990 to 2002, with a two-year hiatus for model years 1997 and 1998, in which the Infiniti I30 became their entry-level car. It was a rebadged version of the Nissan Primera sedan, primarily designed for the European market, and was the result of Nissan's Project 901 initiative. It was launched in September 1990 as Infiniti's first small car as an entry-level alternative to the Q45; later advertisements in 1998 for the second-generation G20 emphasized its European heritage with the tag line "Born in Japan. Educated in Europe. Now Available in America." Two generations of the G20 exist in the United States, the HP10, built from 1990 to 1996, and the HP11, built from 1998 to 2002. All G20s were front-wheel drive and were built in Oppama, Japan. The exterior and interior designs of the P10 were styled by Mamoru Aoki in 1987.The G20 was first unveiled to Infiniti dealers at the 1989 New York International Auto Show, with the first series production example being assembled on July 10, 1990. The final 1996 G20 was rolled off the assembly line on July 19, 1996. The P10 featured the first application of Nissan's multi-link front suspension in a front-wheel-drive car, with an independent MacPherson strut setup in the rear. It came standard with a 5-speed manual transmission. The only options to begin with were an automatic transmission, leather interior, and a power glass moonroof; a Touring package was introduced in 1994 and featured a black leather interior with sport front bucket seats and fold-down rear seats, as well as a limited-slip differential in the transmission and a spoiler on the rear decklid. In Canada, the limited-slip differential was standard with all manual transmission equipped cars from 1990 onwards, with no "t" distinction until the American model started with the model suffix.
Engine design
The G20 was powered by the SR20DE Inline 4-cylinder. It was a transversely-mounted dual overhead cam naturally aspirated reciprocating internal combustion engine. Displacement was with a square bore × stroke ratio of. This engine was also shared with the US-spec Nissan Sentra/Nissan 200SX SE-R, Nissan NX2000, and a host of non-US Nissan vehicles. The particular version used in the G20 produced crank in the US and of torque. These engines were also fairly high-revving for the time, with a redline of 7500 rpm.There were three major variants of the SR20DE used in the G20. The first, used from July 1990 to December 1993, was the highport, in which the injectors and fuel rail were located above the intake plenum. In January 1994, due to tightening emissions restrictions, Nissan switched to a lowport design, in which the injectors and fuel rail switched places with the intake plenum. This design also featured a milder intake camshaft. This design was used from 1994 to 1996 and again in 1998. In 1999 Nissan replaced the valvetrain with a roller-rocker arm lifter design in place of the hydraulic rocker arm previously used, but kept the lowport intake design; many performance parts are not interchangeable between roller-rocker and highport/lowport engines, most notably camshafts.
Transmission
The G20 featured either a 5-speed manual transmission or an optional 4-speed automatic. Most front wheel drive transmissions from other SR-powered cars can be used with few modifications. The stock transmission as well as other SR20 transmissions are often upgraded with various modifications in order to handle more power. Common manual transmission modifications include cryo treating, shot peening, transmission case welding, aftermarket limited slip differential, aftermarket axles, and upgraded clutches. Common automatic transmission modifications include built valve bodies, aftermarket torque converters, automatic transmission fluid coolers, additional ATF filters, and aftermarket TCUs. Higher rated transmission swaps from front-wheel drive VQ or QR25DE powered cars such as the 2002–2006 Nissan Sentra SE-R Spec-V have also been performed.Equipment
The G20 was a badge-engineered version of the Nissan Primera, but because Infiniti was pitched as a premium brand, it featured a high level of equipment compared to its European and Japanese relatives. The only engine available was the 2.0 litre SR20DE Inline 4-cylinder; in Europe this was the top-of-the-line engine for the Primera lineup. 5-speed manual and 4-speed automatic transmissions were both available, with the 5-speed being praised as "one of the best in the business." Power windows, power locks, power mirrors, air conditioning, four-wheel disc brakes with ABS, alloy wheels, a Bose stereo, a theft-deterrent system, cruise control, floor mats, and a leather-wrapped steering wheel and gearshift knob were all standard. Heated mirrors, leather seats and a power moonroof were common options, and were later offered in a package that included power seats and keyless entry. Later models also featured dual front airbags. The standard trim was called Luxury. Two major trim package upgrades were offered: Touring, badged G20t, available from model years 1994 to 1996 and 1999 to 2001, and Sport which was offered during model year 2002. These packages featured a limited-slip differential in the transmission, sportier, more highly bolstered front bucket seats and fold-down rear seats, all-black leather interior, fog lamps, and a spoiler on the rear decklid. The details of these trims varied from year to year.P10 model refresh changes
Introduced at the 1993 New York Auto Show, the main changes for the P10 came as a midyear refresh in April 1993, when dual airbags replaced motorized seatbelts, leather interiors came standard with power front seats, matte-black side moldings were replaced by body-colored ones, the refrigerant was converted from R12 to R134a, the audio system was upgraded to six speakers with a CD player instead of the previously-standard cassette deck, and other new options such as remote keyless entry were added. In February 1994, the 1994 model year was given a new larger chrome-plated grille and door handles, a lowport engine, a change in the vehicle's self-diagnostic system to OBD-II, and larger 195/65R14 tires. The Touring models, introduced in February 1994, featured a limited-slip differential in the transmission; 195/65R14 Yokohama tires, sportier, more highly bolstered black leather front bucket seats and fold-down rear seats; fog lights; and a spoiler on the rear decklid.The G20 was temporarily discontinued after the 1996 model year, leaving the I30 as Infiniti's lowest-priced car for the 1997 & 1998 model years.