The first 1991 G20 was completed on July 10, 1990. The final 1996 G20 was completed 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 (labeled G20t) 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.
The G20 was powered by a transversely mounted DOHC NA reciprocating internal combustion engine, the SR20DE, a 2.0litre (1998cc) square (Bore × Stroke: 86.0 × 86.0 mm) Inline 4-cylinder. 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 140 crank horsepower in the US at first, and 145 in '00+ editions (116 to 126whp; stock range) and 132lb·ft (179N·m) or 136lb·ft (184N·m) torque (111 to 120wft·lbf; stock range). These engines were also fairly high-revving with a redline of 7500rpm for 1991 through 1996 editions, 6950rpm for the 1999 edition, and 6750rpm for 2000+ editions. Due to the SR20DE engine's flexibility, reliability, fuel economy and high power-handling capabilities, as well as a low buy-in cost, pre-owned SR-powered Sentras, 200SXs and G20s have become popular and prominent in the "tuner" or "import scene" subculture.
There were three major variants of the SR20DE used in the G20. The first, used from 1991 to 1993.5, was the highport, in which the injectors and fuel rail were located above the intake plenum. In 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; switching it out for the highport intake cam is a popular upgrade to gain more power. This design was used from 1994 to 1996 and again in 1999. In 2000 Nissan replaced the valvetrain with a roller-rocker arm lifter design in place of the (non roller) 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.