The Porsche 928 is a grand tourer automobile made by Porsche AG of Germany from 1978 model year to 1995 model year, during which time it was one of their most expensive offerings.

Porsche's marketing slogan "It's about as fast as you can go without having to eat airline food" or "It is as fast as you can go without hiring a flight attendant" from the late 1980s where at one point it was the fastest production road-car in the world, having been recorded at 172mph on the salt flats in Utah in 1986 using an early 928 S4. This particular car was originally white but was sprayed bright red for the record attempt to make it stand out more against the salt in marketing material like videos and posters.

Conception
By the late 1960s, Porsche had changed significantly as a company, and executives including owner Ferry Porsche were toying with the idea of adding a luxury touring car to the line-up. Managing Director Ernst Fuhrmann was also pressuring Ferdinand to "greenlight" development of the new model in light of concerns that the current flagship at the time, the 911, was quickly reaching its maximum potential where it could soon no longer be improved upon. Slumping sales of the 911 seemed to confirm that the model was approaching the end of its economical life cycle. Fuhrmann envisioned the new range-topping model as being the best possible combination of a sports coupe and a luxury sedan, something well equipped and comfortable enough to be easily driven over long distances that also had the power, poise and handling prowess necessary to be driven like a sports car. This set it apart from the 911, which was a pure sports car.

Ordered by Ferry Porsche to come up with a production-feasible concept for his new model, Fuhrmann initiated a design study in 1971, eventually taking from the process the final specs for the 928. Several drivetrain layouts were considered during early development, including rear and mid-engined designs, but most were dismissed because of technical and/or legislative difficulties. Having the engine, transmission, catalytic converter(s) and exhaust all cramped into a small rear engine bay made emission and noise control more difficult, something Porsche was already facing problems with on the 911 and wanted to avoid. After deciding that the mid-engine layout didn't allow enough room in the passenger compartment, a front engine/rear wheel drive layout was chosen. Porsche also feared at the time that the U.S. government would ban the sale of rear-engined cars in response to the consumer outrage over the Chevrolet Corvair, started by Ralph Nader via his book "Unsafe at Any Speed".

Porsche engineers wanted a large-displacement motor to power the 928, and prototype units were built with a 5.0 L V8 producing close to 300 hp. Very early units used one four-barrel carburetor, which was eventually tossed in favor of Bosch's K-Jetronic fuel injection system. When increasing concern within the company over the pricing and availability of fuel during the oil crisis of the 1970s became an issue of contention, smaller engines were considered in the interest of fuel economy. Some managers began pushing for development of a 3.3 L 180 hp powerplant they had drawn up specs for, but company engineers balked at this suggestion. Both sides finally settled on a 4.5 L, SOHC 16-valve V8 producing 240 PS (219 hp in North America), which they considered to have an acceptable compromise of performance and fuel economy.

The finished car debuted at the 1977 Geneva Motor Show before going on sale later that year as a 1978 model. Although it won early acclaim for its comfort and power, sales were slow. Base prices were much higher than that of the previous range-topping model and its larger size and somewhat odd futuristic styling put off many purists who were more attracted to more compact 911.

Fuhrman's replacement, Peter Schutz, decided that the models should be sold side by side, feeling that the 911 still had potential in the company's line-up. Legislation against rear-engined vehicles also didn't materialize. Although the 928 developed an avid fan following, it never sold in the numbers that Fuhrmann had originally predicted and was discontinued in 1995. The size of the market for expensive and extravagant grand tourers has increased since then, and the company is again looking to capture this market with the Porsche Panamera four-door GT.

Design

The 928 featured a large, front-mounted and water-cooled V8 engine driving the rear wheels. Originally displacing 4.5 L and featuring a single overhead camshaft design, it produced 219 hp (163 kW/222 PS) for the North American market and 240 PS (176 kW/237 hp) in other markets. Porsche upgraded the engine from mechanical to electronic fuel injection in 1980 for US models, although power remained the same. This design marked a major change in direction for Porsche (started with the introduction of the 924 in 1976), whose cars had until then used only rear- or mid-mounted air-cooled flat engines with four or six cylinders.

Porsche utilized a transaxle in the 928 to help achieve 50/50 front/rear weight distribution, aiding the car's balance. Although it weighed more than the difficult to handle 911, its more neutral weight balance and higher power output gave it similar performance on the track. The 928 was regarded as the more relaxing car to drive at the time. It came with either a five-speed dog leg manual transmission, or a Mercedes-Benz-derived automatic transmission, originally with three speeds, with four speed from 1983 in North America and 1984 in other markets. More than half of production had the automatic transmission. Exact percentage of manual gearbox cars for entire production run is not known but its believed to be between 25 and 30%.

The body, styled by Wolfgang Möbius under guidance of Anatole Lapine, was mainly galvanised steel, but the doors, front fenders and hood were aluminium. It had a substantial luggage area accessed via a large hatchback. The new polyurethane elastic bumpers were integrated into the nose and tail and covered in body-coloured plastic; an unusual feature for the time that aided the car visually and reduced its drag. Porsche opted not to offer a convertible variant but some aftermarket modifiers offer convertible conversions.

The 928 qualified as a 2+2, having two small seats in the rear. Both rear seats could be folded down to enlarge the luggage area, and both the front and rear seats had sun visors for occupants. The 928 was also the first vehicle in which the instrument binnacle moved with the adjustable steering wheel, a feature seen more recently on Nissan's 350Z sports car.

The 928 included several other innovations such as the "Weissach Axle", an early all-wheel steering system that provides passive rear-wheel steering in certain off-throttle cornering situations, and an unsleeved, silicon alloy engine block made of aluminium, which reduced weight and provided a highly durable cylinder bore. The concept of all-wheel steering was also adopted later on to several Japanese automobiles, including a Japanese-market version of the Toyota Celica, the Mitsubishi 3000GT VR-4 and the second generation Nissan 300ZX.

Porsche's design and development efforts paid off during the 1978 European Car of the Year competition where the 928 won against the BMW 7-series and the Ford Granada. The 928 is the only sports car so far to have won this competition, where the usual winners are mainstream hatchbacks and sedans/saloons from major European manufacturers. Proof of how advanced the 928 was compared to its contemporaries.