The G-Series saw significant mechanical upgrades, particularly in the engine department. The iconic 2.0-liter, 2.2-liter, and 2.4-liter flat-six engines were replaced by a new 3.0-liter and 3.2-liter flat-six, producing between 180 and 245 horsepower. The G-Series also introduced a new range of transmissions, including a four-speed manual, a five-speed manual, and an optional three-speed automatic.

The flat-six air-cooled engine grew from 2.7 litres to 3.0 litres in the SC (Super Carrera), and eventually to 3.2 litres in the final Carrera models.

The G-series debuted wearing forged aluminum five-spoke Fuchs wheels (6x15") with a distinct black anodized center. Later, to reduce costs, Porsche introduced the one-piece, cast-aluminum "Cookie Cutter" (or "Tele-dial") wheels, which remain a divisive aesthetic choice today.