|Body and chassis|
|Body style||2-door coupe|
|Engine||4.5 L V8 4.7 L V8 5.0 L V8 5.4 L V8|
|Transmission||5-speed manual 3-speed automatic 4-speed automatic|
|Wheelbase||2,500 mm (98 in) 1988–1995: 98.4 in (2,499 mm)|
|Length||4,520 mm (178 in) 1988–1995: 178.1 in (4,524 mm)|
|Width||1,890 mm (74 in) 1987–1992: 72.3 in (1,836 mm) 1993-95: 74.4 in (1,890 mm)|
|Height||Pre-1989: 50.2 in (1,275 mm) 1990-95: 1,282 mm (50.5 in)|
|Curb weight||1,450 kg (3,200 lb) - 1,620 kg (3,570 lb) (approx)|
The Porsche 928 is a sports-GT car that was sold by Porsche AG of Germany from 1978 to 1995. Originally intended to replace the company's iconic 911, the 928 combined the power, poise, and handling of a sports car with the refinement, comfort, and equipment of a luxury sedan to create what some Porsche executives thought would be a vehicle with wider appeal than the compact, quirky and sometimes difficult 911.
Since its inception in 1949, Porsche has manufactured only six front-engined models, four of which were coupes, including the 928. The car has the distinction of being the company's only coupe powered by a front-mounted V8 engine, and the company's first mass-produced V8 powered model.
By the late 1960s, Porsche had changed significantly as a company, and executives including owner Ferdinand Porsche were playing with the idea of adding a luxury touring car to the line-up. Managing Director Ernst Fuhrmann was also pressuring Ferdinand to approve development of the new model in light of concerns that the current flagship model 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 economic 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 may have feared that the U.S. government would soon ban the sale of rear-engined cars in response to the consumer concern over safety problems with the rear-engined Chevrolet Corvair. The Corvair's alleged safety issues were detailed in the book Unsafe at Any Speed by consumer advocate Ralph Nader.
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 (220 kW). Ferdinand Piëch wanted this car to use a 4.6 liter V10 with 88 mm bore spacing based upon Audi's five-cylinder engine. This five-cylinder is a derivative of the Volkswagen Golf EA827 engine, basically a four with another cylinder added. Several members of the Porsche board objected; their official objection was because they wanted Porsche AG to maintain some separation from Volkswagen. The possible reason was that they didn't want their crowning car to be powered by a variant of the lowly VW Golf engine. Interestingly, this same proposed engine [albeit with greater displacement] was eventually built and installed in a production sports car— the Lamborghini Gallardo. To this day, no Porsche has ever used an EA827-based engine. Until 2011 they used a version of the VW VR6 engine in the Cayenne , but that motor is not related to the EA827 design.
The Porsche 928 engine
The resulting M28 engine eventually designed has multiple unusual features. Its bore spacing is 122 mm, almost exactly the same size as a Chrysler 426 hemi or a big block Chevrolet engine, so it is correct to call it a big block V8. This engine uses thick aluminium cylinder barrels, hence the lower displacement. The engine was designed for air flow first, thus the spark plugs are located top of the head. The four-bolt bearings are massive, and are fed oil via grooves in the bottom surface of the block. The oil and water pumps are powered by the timing belt, and the design of the engine allows for sufficient air flow with a very low hood.
The first two running prototypes of Porsche's M28 V8 used one four-barrel carburetor, but this was just for initial testing. The cars were sold with the planned Bosch 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. A push began for the development of a 3.3 L 180 hp (130 kW) powerplant they had drawn up specs for, but company engineers balked at this suggestion. Both sides finally settled on a 4.5 L, DOHC 16-valve V8 producing 240 PS (180 kW; 240 hp) (219 hp (163 kW) 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 rangetopping 911 model and the 928's front-engined, water-cooled design put off many Porsche purists.
Fuhrmann'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 did not materialize. Although it never sold in the numbers Fuhrmann envisioned, the 928 developed an avid fan following and enjoyed an eighteen-year production run.
The 928 featured a large, front-mounted and water-cooled big-block 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 237 hp (176 kW/240 PS) 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 Porsche 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 80% had the automatic transmission. Exact percentage of manual gearbox cars for entire production run is not known but its believed to be between 15 and 20%.
The body, styled by Wolfgang Möbius under guidance of Anatole Lapine, was mainly galvanized steel, but the doors, front fenders, and hood were aluminium in order to make the car more lightweight. 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 several aftermarket modifiers offered convertible conversions, most notably Carelli, based in Orange County, CA. The Carelli conversions were sold as complete cars, with the conversion doubling the price of the car. A reported 12 units were made.
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 rear seats are small due to the prominent transmission hump [the rear seats have leg room like a front drive car due to the rear transmission], and are only suitable for children, or for typical adults on a short trip. The 928 was also the first vehicle in which the instrument cluster moved along with the adjustable steering wheel in order to maintain maximum instrument visibility.
The 928 included several other innovations such as the "Weissach Axle", a simple rear-wheel steering system that provides passive rear-wheel steering to increase stability while braking during a turn, and an unsleeved, silicon alloy engine block made of aluminium, which reduced weight and provided a highly durable cylinder bore.
Porsche's design and development efforts paid off during the 1978 European Car of the Year competition where the 928 won ahead of 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. This is regarded as proof of how advanced the 928 was compared to its contemporaries.
Styling was the same in both 1978 and 1979, with the body lacking both front and rear spoilers. From 1980 (1983 in North America) through 1986, front and rear spoilers were present on "S" models, rear spoilers being integrated into the hatch. From 1987 through 1995, the front spoiler is integrated into the nose and the rear spoiler became a separated wing rather than an integrated piece, and side skirts were added. The rear tail-light configuration was also different from previous versions. GTS models had wider rear fenders added to give more room for 9" wide wheels. Another easily noticeable visual difference between versions is the style of the wheels. Early 928s had 15" or 16" "phone dial"-style wheels, while most 1980s 928s had 16" slotted "flat discs", CSs, SEs and 1989 GTs had 16" "Club Sport" wheels, later GTs had 16" "Design 90" style wheels which were also option on same period S4s, the GTS used two variations of the 17" "CUP" wheels.
Porsche introduced a refreshed 928 S into the European market in 1979 model year, although it was summer of 1982 and MY 1983 before the model reached North America. Externally, the S wore new front and rear spoilers and sported wider wheels and tires than the older variant, but the main change for the 928 S was under the hood, where a revised 4.7 L engine was used. European versions debuted with 300 PS (221 kW/297 hp), and were upgraded to 310 PS (228 kW/306 hp) for 1984 model year, though it is rumored [and proven on chassis dynamometers] that they typically made around 330 hp. From 1984 to 1986, the ROW (Rest of World) S model was called S2 in UK. These cars used Bosch LH-Jetronic fuel injection and purely electronic Bosch ignition, the same systems used on the later 32-valve cars, though without the pollution controls. North American-spec 1983 and 1984 S models used, among other differences, smaller valves, milder camshafts, narrower intake manifolds, and additional pollution equipment in order to meet emissions regulations, and were limited to 234 hp (174 kW/230 PS) as a result.
As the faster ROW or "Euro" model was not available in the United States and Canada during the first three years of its existence, a "Competition Group" option was created to allow North American customers to have an S model lookalike with spoilers, 16" flat disc wheels, sport seats, sport springs and Bilstein shocks. Customers could specify paint and interior colors the same way as on a normal 928. The package was available in 1981 and 1982 model years and was canceled in 1983 when the S model became available for these markets. Many cars have had S model features added by subsequent owners, making original "Competition Group" cars difficult to distinguish without checking option codes.
In 1982 model year, two special models were available for different markets. 205 "Weissach Edition" cars were sold in North America. Unusual features were champagne gold metallic paint, matching brushed gold flat disc wheels, two-tone leather interior, a plaque containing the production number on the dash and the extremely collectible three-piece Porsche luggage set. It's believed these cars were not made with S spoilers even though these were available in U.S. during this time period as part of the "Competition Group" option. The "Weissach Edition" option was also available for the US market 911 in 1980 model year and 924 in 1981 model year.
140 special "50th Jubilee" 928 S models were available outside the U.S. and Canada to celebrate the company's 50 year existence as a car manufacturer. This model is also sometimes referred to as the "Ferry Porsche Edition" because his signature was embroidered into the front seats. It was painted meteor metallic and fitted with flat disc wheels, wine red leather and special striped fabric seat centers. Similar 911 and 924 specials were also made for ROW markets.
Porsche updated the North American 928 S for 1985, replacing the 4.7 L SOHC engine with a new 5.0 L DOHC unit sporting four valves per cylinder and producing 288 hp (215 kW/292 PS). Seats were also updated to a new style. These cars are sometimes unofficially called S3 to distinguish them from 16-valve ROW "S" models. European models kept a 4.7 L engine, which was somewhat more powerful as standard, though the American-spec 32-valve engine together with catalytic converters became an option in some European countries and Australia for 1985. In 1986, revised suspension settings, larger brakes with 4-piston calipers and modified exhaust was installed on the 928S, marking the final changes to old body style cars. These were straight from the 928S4, which was slated to debut a few months later. These changes came starting from VIN 1001, which means that the first thousand '85's had the old brakes, but later cars had the later systems. This later 1985 model is sometimes referred to as a 19861⁄2 or 1985.5 because of these changes. The name is a little misleading as more than 3/4 of the 1985 production had these updates.
The 928 S4 variant debuted in the second half of 1986 as a 1987 model, an updated version of the 5.0 L V8 for all markets producing 320 PS (235 kW/316 hp), sporting a new single-disc clutch in manual gearbox cars, larger torque converter in automatics and fairly significant styling updates which gave the car a cleaner, sleeker look. S4 was much closer to being a truly world car than previous models as only major differences between ROW and US models were instrumentation in either kilometers or miles, lighting, front and rear bumper shocks and the availability of catalytic converters in many ROW markets. The Australian market version was only one with different horsepower rating at 300 PS (221 kW/296 hp) due to preparation for possible low grade fuel. Even this was achieved without engine changes.
A Club Sport variant which was up to 100 kg (220 lb) lighter became available to continental Europe and U.S. in 1988. This model was watered down version of the 1987 factory prototype which had a lightened body. Also in 1987 the factory made four white lightened manual gearbox S4 models for racecar drivers who were on their payroll at the time. These were close to same as later actual Club Sport models and can also be considered prototypes for it. An SE (sometimes called the S4 Sport due to model designation on rear bumper), a sort of halfway point between a normally equipped S4 and the more race-oriented Club Sport, became available to the UK. It's generally believed these Porsche Motorsport-engined cars have more hp than the S4. They utilize parts which later became known as GT pistons, cams, engine ECU programs and a stronger, short geared manual gearbox. The automatic gearbox was not available.
For the 1989 model year, a visible change inside was digital trip computer in dashboard. At the same time Australian models received the same 320 PS (235 kW/316 hp) engine management setup as other markets. Porsche debuted the 928 GT in the late winter 1988/89 after dropping the slowly selling CS and SE. In terms of equipment, the GT was like the 928 SE, having more equipment than a Club Sport model but less than a 928 S4 to keep the weight down somewhat. It had the ZF 40% limited-slip differential as standard like the Club Sport and SE before it. Also like the CS and SE, the GT was only available with a manual gearbox. ROW 1989 CS and GT wheels had an RDK tire pressure monitoring system as standard. This was also optional for the same year ROW S4. For 1990 model year Porsche made RDK and a 0-100% variable ratio limited-slip called PSD (Porsche SperrDifferential) standard in both GT and S4 models for all markets. This system is much like the one from the 959 and gives the vehicle even more grip. In 1990 the S4 was no longer available with a manual gearbox.
The S4 and GT variants were both cut at the end of 1991 model year, making way for the final version of the 928. The 928 GTS came for sale in late 1991 as a 1992 model in Europe and in spring of 1992 as an early 1993 model in North America. Changed bodywork, larger front brakes and a new, more powerful 5.4 L, 350 PS (257 kW/345 hp) engine were the big advertised changes; what Porsche wasn't advertising was the price. Loaded GTS models could eclipse US$100,000 in 1995, making them among the most expensive cars on the road at the time. This severely hampered sales despite the model's high competency and long standard equipment list. Porsche discontinued the GTS model that year after shipping only 77 of them to the United States. Total worldwide production for all years was a little over 61,000 cars.
Second-hand models' value decreased as a result of generally high maintenance costs due largely to spare parts that are expensive to manufacture. The earliest versions, however, especially those models with the Bosch K-Jetronic (CIS) injection system, have few electronic components and therefore can be repaired more easily provided spare parts can be found. Parts suppliers supported by various enthusiasts exist especially in the United States.
The GTS model has retained a high value however, and as of 2006 the price for all variants is apparently starting to creep upwards.
With the release of the Cayenne SUV, Porsche has met with renewed success with a front-engined, V8-powered model. The company's 2005 announcement that a new V8-powered 4-door grand tourer model called Panamera would be launched in 2009 fueled rumors and fan speculation of a reborn 928. Although the Panamera will be a 4-door model, Road and Track magazine published a speculative piece in their April 2006 issue regarding the possibility of a new, 928-esque coupe that may debut on a shortened version of the Panamera's platform sometime around 2011 or 2012 model year. As of January 2013, no announcement has been made by Porsche that could add credibility to this speculation.
The Porsche 942 was a special edition 928 presented by the company as a gift to Ferry Porsche on his 75th birthday in 1984. Its also known by name 928-4, 928S. It featured 10 in (254 mm) longer wheelbase than normal 928 production model, including an extended roof above the rear seats to better accommodate tall passengers, at the time very advanced projector headlights, the 5 liter 32-valve engine before it was introduced in US market, and S4 front and rear bumpers two years before they entered production.
"Study H50" Four-door 928 based prototype
Three years later, in 1987, the lengthened 928 that had been presented to the company's founder on his 75th birthday turned up as a "Feasibility Study", now with a second (rather narrow) set of doors, apparently opening in the same way as the doors on the twenty-first century Mazda RX-8. At the time "Study H50" appeared to sink with little trace, but two decades later, with the launch of the larger four-door Porsche Panamera, the 928 based four-door prototype from 1987 acquired greater significance.
928 long wheelbase specials
In 1986 Porsche together with tuning company AMG made few long wheelbase 928 specials. Unlike 942, these had normal 928 headlights. One was presented to American Sunroof Corporation (ASC) founder and CEO Heinz Prechter. ASC was later partly responsible of making Porsche 944 S2 cabriolets.
The Max Moritz 'Semi Works' 928 GTR
Porsche's Racing Department never officially entered or prepared a racing 928 for a pure works entry. Only once Porsche decided to make it obvious to the 911 enthusiasts that they usually tended to underrate the racing genes of the 928. Porsche then "arranged" this 928GTR to compete against the then dominant 911(993GTR) on the race track. In order not to offend sensibilities of their traditional 911/993GTR customers by officially challenging them with an outright Works - 928GTR, Porsche asked Max Moritz Racing, their longtime private racing partner from next door Reutlingen to enter this 928GTR Cup as a 'semi-works' car.
It didn't come as a surprise that the drivers were: Bernd Mayländer, Manuel Reuter (Porsche works pilots), also Harm Lagaay (then Head of Porsche's Design Studio). Vittorio Strosek sponsored MM with his Lightweight-Body-Parts and racing exhaust. The car was officially entered by Porsche-Club-Schwaben. Homologation minimum weight had to be, and actually is 1,370 kg (3,020 lb).
Lagaaij reports that the car was very competitive and able to hold most 964 CUP GTs down, although the engine was no more than fine-tuned after having been chosen from a set of high power output specimen in Weissach. In the last race of the season at Hockenheim a crank-bearing ran dry. As the car was supposed to race in 1995 as well, she was made ready to continue her successful competition in the 1995 season. A fresh engine was installed, selected from the same lot of high output engines and tuned as before. In 1995 Porsche's 928 production came to an end, and the car consequently was not raced in the new season.
The late Max Moritz himself then had her join his collection of historic cars. She was not put on the road again until after his death, when the family sold the car in October 2004 - with only 24500 km on the clock (Porsche-Weissach is the only documented owner).