Porsche introduced a refreshed 928 S into the European market in the 1980 model year, although it was the 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 , and were upgraded to for the 1984 model year. From 1984 to 1986, the S model was called S2 in United Kingdom. These cars used Bosch LH-Jetronic fuel injection system and purely electronic Bosch ignition, the same systems used on the later 32-valve cars. North American-spec 1983 and 1984 S models used among other differences, smaller valves, milder camshafts, smaller diameter intake manifolds, and additional pollution equipment in order to meet emissions regulations, and were limited to as a result. Due to low-grade fuel, the 16-valve low compression S engine was made for the Australian market in the 1985 model year. It had a 9.3:1 compression ratio pistons as opposed to the normal 10.4:1 but used the same large intake, high lift cams, large valves, etc. of other S engines. During the initial three years of its production, the faster European variant of the Porsche 928 was not available in the United States and Canada. To address this, Porsche introduced a "Competition Group" option for North American customers, offering them a package that mimicked the appearance of the S model. This package included front and rear spoilers, 16-inch flat disc wheels, sport seats, sport springs, and
Bilstein Shock Absorbers. Customers had the flexibility to choose paint and interior colors just like with a standard 928. Only two cars were produced with this option in the late 1980 model year for the U.S. market. The package officially became available for the 1981 and 1982 model years but was discontinued in 1983 with the introduction of the S model in these markets. Over time, many cars have been modified by subsequent owners to include S model features, making original "Competition Group" cars difficult to identify without checking option codes. In the 1982 model year, two special models were introduced for different markets. North America received 202 "Weissach Edition" cars, featuring champagne gold metallic paint, matching brushed gold flat disc wheels, two-tone leather interior, a production number plaque on the dashboard, and a three-piece Porsche luggage set. It's worth noting that these cars were believed not to be equipped with S spoilers, despite the availability of S spoilers in the U.S. during this period as part of the "Competition Group" option. The "Weissach Edition" option was also offered for the US market 911 for the 1980 model year and the 924 for the 1981 model year. 141 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 featured meteor metallic paint and was fitted with flat disc wheels, wine red leather and special striped fabric seat centers. Similar 911 and 924 specials were also made for world 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 . Seats were also updated to a new style, these cars are sometimes unofficially called S3 to distinguish them from 16-valve "S" models. European models kept a 4.7 L engine, which was somewhat more powerful as standard, though lower 9.3:1 compression 32-valve engine together with catalytic converters became an option in some European countries and Australia for 1986. In 1986, revised suspension settings, larger brakes with 4-piston callipers, and a modified exhaust system was available on the 928S, marking the final changes to old body style cars. These were straight from the 928S4, which was to debut a few months later. These changes came starting from VIN 1001, which means that the first thousand 1986 cars had the old brakes, but later cars had this equipment available. This later 1986 model is sometimes referred to as a 1986 or 1986.5 because of these changes. The name is a little misleading as more than 3/4 of the 1986 production had these updates.
928 S4 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 , sporting a new single-disc
clutch in
manual transmission cars, a larger torque converter in automatic transmission cars and fairly significant styling updates which gave the car a cleaner, sleeker look. The 928 S4 had a rounded front end with air intakes. The rear had a slope between the wide, flush-fitting rear lights and a Black rear spoiler standing up from the body. S4 was much closer to being a true world car than previous models as the only major differences for North American models were instrumentation in either kilometers or miles, lighting, front and rear bumper shocks, and the availability of catalytic converters in many other markets. The Australian market version was the only one with different horsepower rating at due to preparation for possible low grade fuel. Even this was achieved without engine changes. A Club Sport variant which was up to lighter became available to continental Europe and U.S. in 1988. This model was the toned down version of the 1987 factory prototype which had a lightened body. Also in 1987, the factory made five white lightweight S4 models with a manual transmission for racecar drivers who were on their payroll at the time (Derek Bell, Jochen Mass, Hans Stuck, Bob Wollek and Jacky Ickx). 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 for the UK market. It's generally believed that these cars have more power than the usual S4. They utilize parts which later became known as GT pistons, cams and engine ECU programs. Some of them had stronger, short ratio manual transmission. The
automatic transmission was not available for this model. For the 1989 model year, a visible change inside was
digital trip computer in the dashboard. At the same time Australian models received the same engine management setup as other markets. Porsche debuted the 928 GT in the late winter 1988/89 after dropping the slow-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. European 1989 CS and GT wheels had an RDK tire pressure monitoring system as standard, which was also optional for the same year S4. For the 1990 model year Porsche made RDK and a 0-100% variable ratio limited-slip called PSD (Porsche Sperr Differential) standard in both GT and S4 models for all markets. This system is much like the one from the flagship
959 and gives the vehicle even more grip on the track. In 1990, the S4 was no longer available with a manual transmission.
928 GTS The S4 and GT variants halted production at the end of the 1991 model year, making way for the final version of the 928. The 928 GTS was available 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, 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 high maintenance costs due to spare parts that are expensive to manufacture. Many parts suppliers and enthusiast networks exist, especially in the United States, Germany and the UK.
Road & Track magazine published a speculative piece in their April 2006 issue regarding the possibility of a new, 928-esque coupé that may debut on a shortened version of the
Panamera's platform sometime around 2011 or 2012 model year but this speculation remained uncredible as Porsche denied the possibility of any such model reaching production stage. ==Timeline==