By the early 1970s, it was clear that tough emissions and safety regulations were changing the American market. Since the U.S. was Porsche's biggest market, executives decided to develop a new model that met all federal regulations. If Porsche had to kill the 911, it would be prepared to transition. Plans for the new 928 began in October 1971, and were finalized in 1972. For the U.S., a front-engine, rear-wheel-drive V-8 Grand Touring car made sense.
The Porsche 928 debuted in March 1977 at the Geneva Auto Show, and received much acclaim. At first glance, the car looked similar to the Porsche 924 - a low, wide stance, a long, sloping hood, sharp nose, and rounded tail. But the 928 was a different beast altogether.
Beneath the skin lay an advanced and well-balanced power train. A 90-degree, all-aluminium, 16-valve, 4.5-litre V-8 with Bosch Continuous Injection System (CIS) fuel delivery produced 219hp and 254ft-lb of torque. It was mated to a synchronized rear transaxle with either a 5-speed manual or optional 3-speed automatic, and weight distribution was nearly perfect at 51%/49%.
Suspension was fully independent, and Porsche worked hard to perfect the 928's rear multi-link setup, which would allow it to accommodate over-aggressive drivers without snap over steer. The resulting "Weissach Axle" made the 928 one of the best handlers in the world. The cabin was plush, with supportive leather seats, an ingenious tilt steering/instrument binnacle, and the comforts of a luxury GT. It was fast, with 0 to 60mph at 7 seconds, and a top speed of 140mph. The 4.7-litre 928S of 1983 was rated at 146 mph.
Design head Tony Lapine stated that "a car which is liked immediately will not hold up over time." Porsche purists bristled, but Lapine designed a long shelf life into the Porsche 928 and incorporated 5-mph safety bumpers front and rear. The body made use of collapsible polyurethane pieces over front and rear bumpers, with aluminium doors, bonnet, and front wings, with steel for the remaining panels. Trying to coat such different materials with a uniform paint proved challenging.
Displacement, power, and top speed increased as production continued, with a 5-litre V-8 appearing in 1985, as well as revised brake and suspension components and a 4-speed automatic to replace the 3-speed. A 928 S4 debuted in 1987 with 316 hp, and a 928 GT entered the fold in 1989, complete with a limited-slip differential and available only with a 5-speed. The 928 GTS replaced both the S4 and GT for 1993. with freshened bodywork and a bigger 5.4-litre engine. It developed 345hp and was capable of 170 mph. It also cost nearly £50,000.
By this time, the 928 had practically disappeared from the market. Sales had fallen dramatically, and Porsche redoubled its efforts on the 911, which had weathered the regulatory storms relatively unscathed. In all nearly 61,000 Porsche 928s were built during the car's 17-year tenure. Even by modern standards, it is a competent, comfortable GT, and a well-sorted one will offer plenty of high-speed thrills over continental distances. However, all 928 models are complex machines, and comprehensive service records are essential if you want to avoid big mechanical bills. Like all Porsche 924 and 944, although galvanised, the sills can rust and should be inspected closely.