Infiniti G20

The G20 was Infiniti's entry-level luxury car during most of the 1990s and into the 2000s. The G20 was a product of badge engineering as it was virtually identical to the non-USDM (United States domestic market) Nissan Primera sedan, although the G20 offered a different variant of Nissan's 2.0 liter inline 4-cylinder engine. Two generations of the G20 exist in the United States, the HP10 (P10), built from 1991 to 1996, and the HP11 (P11), built from 1999 to 2002. Two major trim packages were offered: Touring, badged G20t, available from model years 1994 to 1996 and 1999 to 2001, and Sport (with no badge modification) which was offered during model year 2002. All G20s were front-wheel drive and were built in Oppama, Japan.

Marketing
The G20 was marketed in the United States as a competitor to European luxury sport coupes such as the BMW 3-series, reflected in advertisements with the tagline "Born in Japan, Educated in Europe, Now Acclaimed in America." Despite the lofty ambitions of the Nissan marketing department, it only achieved niche status as a competitor to other contemporary offerings from Acura and BMW.

Engine
The G20 was powered by a transversely mounted DOHC NA reciprocating internal combustion engine, the SR20DE, a 2.0 liter (1998 cc) Inline 4-cylinder. This engine was also shared with the USDM Nissan Sentra/Nissan 200SX SE-R, Nissan NX2000, and a host of non-USDM Nissan vehicles. The particular engine used in the G20 produced 140 crank horsepower at first, and 145 in '00+ editions (116 to 126 whp; stock range) and 132 lbf or 136 lbf of torque (111 to 120 wft·lbf; stock range). These engines were also fairly high-revving with a redline of 7450 rpm for 1991 through 1996 editions, 6950 rpm for the 1999 edition, and 6750 rpm for 2000+ editions. Like other SR-powered cars, the G20 has become extremely popular among "tuners" who like the engine for its flexibility, reliability, fuel economy and high power-handling capabilities. These factors combined with a low buy-in cost have caused used SR-powered Sentras, 200SXs and G20s to become popular and prominent in the tuner or "import scene" subculture.

First Generation 1991-1996 (P10)
The first 1991 G20 was completed on July 10, 1991. The final 1996 G20 was completed on July 19, 1996. The main changes for the P10 came as a midyear refresh in 1993 (model year 1993.5), when dual airbags replaced motorized seatbelts, leather interiors came standard with power front seats, and the audio system was upgraded to six speakers. In addition, the 1994 model year was given a new chrome grille, body-colored side moldings, a lowport engine (replacing the original highport SR20DE in which the intake plenum is below the fuel injectors and fuel rail), and larger 195/65R14 tires. A new trim line, the "Touring" G20t, came with a sportier black leather interior, fold-down rear seats, and a limited-slip differential. The 1994 model year also saw the air conditioner converted from R12 to R134a refrigerant, a change in the vehicle's self-diagnostic system to OBD-II, and other new options such as remote keyless entry. The G20 was temporarily discontinued after the 1996 model year, leaving the J30 as Infiniti's lowest-priced car for the 1997 model year. However, the J30 was also discontinued in 1997 after the introduction of the larger I30, leaving Infiniti without an entry-level model.

Second Generation 1999-2002 (P11)
The second-generation G20 underwent several changes, including adopting the multi-link beam rear suspension from the 1995-1999 Nissan Maxima. Despite enthusiasts' aversion to the beam, several publications praised the handling of the updated G20. With the increased size and luxury options, however, the stock 140-145 crank horsepower engine was seemingly underpowered. The first 2nd generation 1999 G20 was completed on May 18, 1998. The final 2nd generation 2002 G20 was completed on January 11, 2002. Several noteworthy changes for the P11 came as a refresh in the 2000 model year, when the 145 crank horsepower roller rocker variant of the SR engine was implemented, anti theft immobilizer circuitry was added, anti-glare side mirrors, and a keyless remote trunk release became a feature.

End of Production
The G20 was discontinued in favor of 2003's rear wheel drive G35, a badge engineered export version of the JDM V35 Nissan Skyline which was introduced in 2001. The G35 received significant praise from the automotive press and became a sales success for Infiniti despite being priced approximately USD$5,000 above the G20's average MSRP of $23,000. The G35, significantly larger and more powerful than the G20, was aimed more at the entry luxury-sports car market instead of the G20's luxury-sport compact market. The Nissan Primera was continued as the slightly restyled HP11-144 and the significantly restyled HP12 in non US markets.

Engine Upgrades
Forced induction (turbocharging) is often used to upgrade SR20DE powered G20s to higher levels, as much as 200 to 300 whp. Because the turbocharged SR20DET has a very similar design to the SR20DE, many components from the former can easily be used with the latter. More common than forced induction upgrades are the use of bolt-on aftermarket parts such as intakes and exhausts. Using only the bolt-ons, around 155 whp is possible.

Common engine modifications can include intakes (WAI, CAI), larger MAF, larger fuel injectors, header, exhaust (cat back, axle back), underdrive pulleys, lightened flywheel, camshafts, camshaft gears, pistons, valvetrain (7500 to 9000 rpm), headwork, and stroker kits (up to 2.2 to 2.4 L). As the SR20DE is a popular tuning engine there are also vast numbers of unusual or custom upgrades.

Engine Swaps
With certain SR20DET engine swaps, high levels of around 400 whp are possible. The newer Nissan SR engines can also be swapped into the G20. Factory turbocharged SR20VET Neo-VVL swaps are possible but rare, and output is difficult to estimate. The naturally aspirated SR20VE Neo-VVL can also be used in an engine swap which can (with bolt-ons) generate around 190 whp and can also be turbocharged. VQ35DE swaps are also theoretically possible.

Transmission
Common manual transmission modifications include: Cryo treating, shot peening, transmission case welding, aftermarket LSD, aftermarket axles, and aftermarket clutches. Common automatic transmission modifications include: Built valve body, aftermarket torque converters, ATF coolers, and aftermarket TCU.

Stock manual transmissions are typically usable up to approximately 250 whp, while stock automatic transmissions can only handle about 155 whp. Most front wheel drive transmissions from other SR powered cars can be used with few modifications.

Suspension
Common suspension modifications include lowering springs, shocks, coilovers, strut bars (front and rear), pillow-ball strut mount (front only for P11 with front and rear for P10), sway bar (rear), and traction bars.

Wheels
P10 tire fitments:
 * 195/60/14 - 23.2 in. diameter (35-45 mm offset required) - ('91-'93 P10)
 * 195/65/14 - 24 in. diameter (35-45 mm offset required) - ('93.5-'96 P10)

centerbore = 66.1 mm bolt pattern = 4x114.3 mm

P11 tire fitments:
 * 195/65/15 - 25 in. diameter (35-45 mm offset required) - ('99-'02 Standard)
 * 195/60/15 - 24.2 in. diameter (35-45 mm offset required) - ('99-'01 Touring)
 * 205/50/16 - 24.1 in. diameter (35-45 mm offset required) - ('02 Sport)

centerbore = 66.1 mm bolt pattern = 4x114.3 mm

Brakes
Common brake modifications can include calipers, pads, and steel brake lines. Many brake kits are available.

Other
Aftermarket ECU and various engine management systems are available, as are carbon fiber body parts and various body kits. "Universal" parts such as steering wheels and seats can often be used. Also, several OEM Nissan Primera parts from around the world (primarily JDM and UKDM) can be used such as dual headlights and rain guards. Custom parts are sometimes fabricated by G20 owners; these include fuel rails, brake kits, and custom body pieces (eyebrows, bumper lips, grilles).

G20 community
As with many "tuner" cars, G20 owners have fostered a strong sense of community, largely through the internet. Owners often partake in group buys of brand name products for a collective discount, with some internet forums seeing as many as one group buy request every four days. Members of the community may also congregate in a car tuning "meet", where multiple owners meet in person to talk about their love of the G20 and gain camaraderie with fellow G20 fans.

Common reliability problems

 * Fifth-gear pop-out - On pre-1994 manual transmission models, a flawed 5th gear synchro can cause the transmission to pop out of gear when under load (accelerating or going uphill). To lower chance of pop-out, do not rest one's hand on the gear lever.


 * Blower resistor - Failure of this component can cause the climate control to get stuck at the highest blower setting.


 * "P10 Resistor" - This silver-colored box under the hood can cause the automatic transmission to shift roughly.


 * Power antenna - The mast can get stuck, or the motor can burn out.


 * Automatic seatbelts - Used only in model years 1991-1993, they may get stuck; there is a recall pertaining to this problem.


 * P10 fuel pump failure - occurs with low levels of gasoline. To lower chance of fuel pump failure, remain above 12.5% or 1/8 of a tank; alternately, keep fill-ups under 13.913 gallons.


 * Power steering hose leaks - due to faulty OEM "clamps". Replace them with better aftermarket clamps to avoid possible corrosion of other engine components.


 * Starter motor - Failure of this part is common in both the P10 and P11, particularly in the 2000+ P11.

Awards
The G20 earned many automotive awards over its lifespan:


 * IntelliChoice: 1993 “Best Overall Import Car Value Over $13,000” and “Best Value in Compact Class Over $16,000.”
 * J.D. Power and Associates: 1996 Top Score in Customer Satisfaction Index.
 * J.D. Power and Associates: 1997 Second Highest Scorer in Customer Satisfaction Index.
 * IntelliChoice: 1999 G20 and G20t “A Best Overall Value - Compact Sedan Over $15,000.”
 * CAR Magazine: Rated One of the Top 10 Best Handling Cars in the World (P11)

Enthusiast Web Sites

 * G20.net
 * SR20 Forum
 * SCC article from SE-R.net on P11 Multilink & beam-axle rear suspension