- Available for £16,000
- 5.0-litre V8 32v, rear-wheel drive
- Well-built and characterful GT car
- Old now, but made to last (electrics apart) and looking better with age
- Strong, basic mechanicals, but don’t try to run one on the cheap
- £25k will buy a very good one – but for how much longer?
Hard to believe, knowing what we know now, but in the late 1960s Porsche was about to call time on its 911, thinking it was tapped out in terms of development. To fill what they saw as a worryingly large upcoming gap, plans were hatched for a modern luxury touring car with a powerful water-cooled engine at the ‘right’ end (i.e. the front) driving the rear wheels. This would give Porsche something to pitch against BMW and Mercedes, not just in Germany but also in the US where the air-cooled 911 was running out of boot space to accommodate that country’s emissions gubbins on top of the drivetrain.
The result, in 1977 for sales in 1978, was the 928. The first model’s carburetted 4.5-litre V8 produced just 237hp, and even less than that in the US, which shows how far we’ve come in terms of engine output per litre since. In quite a few other respects however, the 928 was ahead of its time. The engine was almost entirely made out of lightweight alloy. Manufacturers of today’s high-end sports cars like to brag about rear-wheel steering but the 928 had it right from the start, a passive system they called the Weissach axle. It also had an instrument cluster that adjusted with the steering wheel. European Car of the Year judges recognised its innovation and futuristic design by giving it the top gong in 1978. It remains the only sports car winner in ECOTY’s near-60-year history. Apple’s innovator-in-chief Steve Jobs had a white one.
Porsche 911 fans didn’t like it much but the 928 managed to remain a stalwart part of the Porsche offering for the next 18 years. The 928 S that made its debut in 1979 had a 2mm overbore, taking it to 4.7 litres and 295hp, enough to get it past the 250km/h (155mph) barrier. A later hike in the compression ratio and a switch to electronic fuel injection took it over the 300hp mark.
You may remember Tom Cruise driving a 928 in the 1983 movie Risky Business. In 2021 one of the three cars he used in that film was auctioned for just under $2 million. That made it the dearest 928 in history, a record that’s unlikely to be broken. In this buying guide though, we’ll focus on the slightly later 5.0 litre twin-cam 928S 4 version that was announced in 1985 and put on sale in 1986. You’ll be pleased to hear that you can grab one of these for a lot less than two million dollars. How does under £16k sound? You should like the sound of that because, even though you could get 928s for around half that amount at one time, it’s still a hell of a lot of motor for the money – and it’s not hard to see good ones going up further in value.
Faster, more efficient and better equipped than earlier 928s, the 4 could be had from new as a 5-speed manual – the standard spec – or as a 4-speed auto, that having replaced the three-speeder fitted to pre-’84 928s. In manual form, the 4 did the 0-60mph run in the mid-five second bracket. The auto was about half a second slower. Claimed top speeds were 170mph and 165mph respectively, impressive for the day and the claims weren’t overstated either. One of the big American mags got their test car to 166.94mph and Al Holbert recorded nearly 172mph in a pre-production example at Bonneville salt flats, a ratified speed that made it the world’s fastest naturally aspirated production car at the time.
A year after the 928S 4’s 1986 launch Porsche decided to lift the model’s sales profile by building four lightweight manual cars for Derek Bell, Jochen Mass, Hans Stuck and Bob Wollek. A year after that, in 1988, Porsche launched the showroom version of those cars, the 928 Club Sport. In normal Club Sport fashion, enhanced performance was achieved through lightness rather than extra power. Although air con was retained the compressor for it was a smaller. Electric seat adjustment was deleted, as was the rear wiper and PVC undercoating.
There was a trimmed-down wiring harness, a lighter exhaust system and lightweight magnesium wheels. These CSs simply never come up for sale as it’s thought that just 27 were built in 1988 and 1989, of which maybe 15 were released to the public. Most were in Guards Red, the four racers’ cars were in Grand Prix white and a couple were in Forest Green. Specs were pretty much bespoke to what the customer wanted, from a short-throw gearshift to lowered suspension or wider tracks. Derek Bell only sold his one after 18 years of happy driving.
Also in 1988, a manual-only 928S 4 Sport SE model appeared in the UK with a tuned engine and, in some cases, a close-ratio gearbox. They’re not much more common than the CS with just 42 made. The sign-off model for the 5.0 engine was the 1989 928GT which, unlike the Club Sport, did have extra grunt – 325hp compared to the standard model’s 316hp – which trimmed the 0-60mph time by 0.1sec. Thankfully this one is somewhat more accessible than the two we’ve just talked about with 2,078 made between 1989 and 1991, when it was replaced by the restyled and powered-up (345hp) 5.4 litre GTS which we won’t be covering here. The 928 line finally shut down in 1995.
Only ten years ago you practically had to give away 928s to free up space on your drive. Things have changed. Now you’re looking at £15k minimum for a 5.0 4 and that will be for a very leggy example or one with a lot of problems, or very possibly both. For a good car with under 100,000 miles you’ll need to find £25k or more depending on condition and the number of owners. At the end of this piece we’ll link you to a 928 with a price tag that will make you wince, and possibly kick yourself for not buying the one that that bloke was practically giving away to create space on his drive.
SPECIFICATION | PORSCHE 928S 4 5.0 (1986-91)
Engine: 4,957cc V8 32v
Transmission: 5-speed manual or 4-speed auto, rear-wheel drive
Power (hp): 316@6,000rpm
Torque (lb ft): 317@3,000rpm
0-60mph (secs): 5.7 (6.1 auto)
Top speed (mph): 170 (165 auto)
Weight (kg): 1,550
MPG (average): 21.2
Wheels (in): 7 x 16 (f), 8 x 16 (r)
Tyres: 225/50 (f), 245/45 (r)
On sale: 1986-1991
Price new: c. £65,000 (1987)
Price now: from £16,000
Note for reference: car weight and power data is hard to pin down with absolute certainty. For consistency, we use the same source for all our guides. We hope the data we use is right more often than it’s wrong. Our advice is to treat it as relative rather than definitive.
ENGINE & GEARBOX
Porsches have always been very well-engineered, and the 928S 4 certainly followed that example. Good maintenance is of course key to keeping any old engine together. Looked after properly, the S4’s 5.0 should do at least 150,000 miles before needing major work, but even the youngest S 4 is more than 30 years old now and the 928’s time in the wilderness when they were worth very little means that there are plenty of cars on the market with troubling gaps in the service book.
At the very least you want to see that the cambelt, tensioners and water pump have been changed on the factory-recommended 5-years/45,000-mile schedule. It was actually 60,000 to start with but some owners were already working to a shorter schedule to be on the safe side. In mid-2007 Porsche service centres in the US were told to switch to a 10-year/45,000-mile replacement plan. Unlike earlier 928 engines, the 32-valver in the S 4 was an ‘interference’ engine design, which means serious damage to the valvegear if the belt breaks – as it has been known to do with as few as 15,000 miles covered. Nobody is quite sure when the change from non-interference to interference happened but everyone agrees that at nearly seven feet the S 4’s timing belt was one of motoring’s longest. It’s good practice to regularly check the tension and the tensioner shouldn’t be ignored either. That will probably need to be rebuilt at some point. It was relatively easy to change the water pump during the belt work but not so easy to change it with the belt in situ.
If you see that shortened schedule in the paperwork it’s a good indicator of proper care. It would also be handy to see notes on regular coolant changes. Thermostats leak, and if a 928 radiator gets rusty, a process which poor servicing will gladly speed up, it will cost you upwards of £1,000 for a new one. The 5.0 engine gets old car engine ailments like worn bores (the block was linerless) and leaky valve guides, leading to high oil consumption. Mind you, it was high even when everything was OK, like 300 miles per pint high, but oily smoke on startup is bad news and a pretty clear indication that a top-end overhaul is due. The good news with the S4 is that the old stud fastening arrangement for the heads was replaced by more convenient bolts. The less good news is that the head castings on pre-’89 S 4s were on the thin side. ’89 and above cars got thicker castings and longer bolts.
As most of us know, electricity in engine compartments is carried by wires and these get fragile with age, heat and corrosion. This happens on 928s. It’s wise to keep sensors, ground straps and electrics generally clean and treated with water-repellent spray as appropriate. Other stuff can go wrong over time too, like the drive belt that links the 928’s dual distributors. If that belt goes west then so does your car’s smooth running. Crank seals and oil seals generally can stop sealing. ’86-’89 S 4s in particular were not immune to a coming-together of oil and coolant. Problems with the Bosch LH-Jetronic Injection and ignition weren’t unknown either but happily there is plenty of knowledge and no shortage of fixes for more or less everything on an S 4.
The idea of a torque converter transmission from the 1980s might not fill you with joy but the Mercedes-originated 4-speeder that came with the 928S 4 auto could make you a believer. Seven out of ten 928 customers preferred it to the standard manual. You might think this places 928 buyers firmly into the BOF/midlife crisis category, but the truth of the matter was that experienced Porsche hands never really rated the 928 5-speed dogleg, especially in right-hand drive cars, whereas the slusher was a fine match for the torquey V8.
When S 4s were new there were about four autos to every manual, but by our very unscientific assessment of the used market in 2023 the ratio of autos to manuals is now closer to three to one. Maybe manual owners have put more effort into preserving their rarer cars in the hope that they will be rewarded with higher resale values, or maybe auto problems are more expensive to fix and therefore more likely to hasten the demise of a car. Probably a bit of both. Porsche did put plenty of effort into improving the manual, most notably replacing the original twin-plate clutch with a single-plate unit on the S4, but this is one pre-dual-clutch sports car where the trope of ‘you must have a manual’ doesn’t really apply.
The engine thrust bearing was notorious for failing on 928 autos. Left to it, wear in this area would eventually cause the crank to grind away the crankcase, trashing the engine. Automatic transmission fluid was used for the power steering rather than power steering fluid, not sure why, but ATF is flammable and when it ran through old pressurised PAS lines in the 928 it was known to cause a fire or two when the pipes failed. Transaxles could leak.
Quite a few 928s have had complete engine replacements, but not all of them were to the same spec or power as the original (American engines were often less powerful), so again good provenance and paperwork is essential when viewing a car. You want to see a good matchup between what it says on the VIN plate and what the car actually has. As long as you could get near the average consumption figure of 21mpg, which wasn’t that hard thanks to the slippery body shape, the near-19 gallon fuel tank allowed you to put in 400-mile stints between fill ups so it was a genuine GT car.
CHASSIS
Even now you’ll be impressed by how well an S 4 handles. The engine was positioned well back in the bay so the steering was excellent, as were the high-speedq stability, braking and grip. It all contributed to an immense feeling of security in the cocoon-like cabin.
As they did with the drivetrain, Porsche was always tinkering with the 928’s chassis components, not so much ramping everything up in size as has become the fashion these days, more making what was already on there the best it could be based on the premise that the 928 was designed and engineered for optimal performance back in 1978. As far as we know the S 4 had the same double wishbone independent front suspension and Weissach rear axle as that first 928 of 1978 – although Porsche did increase the width of the rear 16-inch rims to 8-inch for the S 4. Bigger brake calipers were added at this time too, and we read somewhere that a limited-slip diff was added to 1990 models.
That programme of improvement obviously stopped with the car in 1995. From then on it’s a simple case of all suspension and brake parts wearing out and you replacing them, or not, depending on how stingy you are. In any big, heavy sports car, worn dampers and bushes will noticeably impact the drive quality. Bush replacement in a 928 requires fairly heavy-duty pressing equipment. Wheel alignment is also important on these.
Power steering systems can leak. An ABS or traction control warning light could be down to a problem with the system’s hydraulic pump which was sited in the left rear quarter panel. This was supposed to be bled whenever the brakes were done. Again, you’ll need to see paperwork on any car you’re thinking of buying, hopefully telling you that lots of replacement items have been fitted over the years. High mileages are quite common on 928s and those who know these cars will tell you that a fully-serviced high-miler is far preferable to a low-miler with gaps in the history.
BODYWORK
The 928’s hatchback body was made of a mix of galvanised steel and aluminium in the doors, front wings and bonnet, and polyurethane in the low-drag bumper sections, but rust could and did get a foothold where the suspension subframes met the body.
Cooling ducts in the nose were electrically opened or closed depending on engine temperature. The rear spoiler became a separate (ie non-integral) item on the S 4 and could be hinged up to grant your chamois access to the bottom part of the tailgate glass. The front spoiler was binned in favour of ground effect panels on the underbody. An electric sliding roof was available as an option, but despite its air deflector it did add a fair bit of additional noise to the tyre roar that was fairly insistent at motorway speeds.
INTERIOR
The S 4 cabin was a fine example of what could be achieved by combining good interior design principles with top-quality materials. It exuded clean, luxurious functionality. The instrumentation binnacle/steering wheel connection meant you could always see the clock faces however you adjusted the wheel. If you are wondering why that excellent-sounding idea was more or less ignored by other car manufacturers, and indeed dropped by Porsche itself, the answer lies in the fact that all the wiring for the instruments was going up and down too and old wiring doesn’t really enjoy that experience. The printed circuit board behind the gauges would delaminate and the plastic tabs that housed the lower two connectors became brittle and broke.
Any electrical switches in the cabin should be checked for correct operation. Some of them probably won’t work so you then have to work out if you’re going to proceed anyway and will probably wish you’d never tested them in the first place. You can check the climate control too but again don’t build your hopes up too much. At this stage, the electrics are probably going to give you a few headaches. Some say you should bin any 928 relay with ‘Bosch’ written on it.
Besides fore and aft adjustment the S 4’s seats had power adjustment for height, tilt and recline as well as a powered in two planes lumbar support for the driver. There was a three position memory function for the seats. The rear seats were for children only if you were doing long journeys but adults who didn’t care about headroom could fit in there for short spurts. A 928 with checked ‘Pasha’ velour would be ultra-cool today in the same way that tartan was in the first Golf GTIs but sadly Porsche was no longer offering that when the S 4 arrived. The longevity of leather made it a more practical choice anyway, although lighter-coloured interiors will almost all look slightly grubby today. Restoring the seats is a worthwhile exercise and there are specialists who will do it for £1,000 or so.
You won’t be surprised to hear that rear three-quarter visibility was on the poor side of average and that the corners of the car were invisible from the driver’s seat – a small price to pay for such a lovely body shape, you might think. Nearly five feet of load space could be created by dropping the rear seats. The shape of the space wasn’t tremendously practical though and the siting of the spare wheel under the rear compartment floor didn’t help.
PH VERDICT
Contemporary ads said that the S 4 was about as fast as you could go without having to eat airline food. It’s a 1970s design but if you knew nothing about cars you’d never guess that. There’s something very right and timeless about it. The S 4 version we’ve looked at here was a carefully executed evolution of the first 1978 car and it still looks special today. The bulky look that scared a few potential buyers off in the car’s formative years is no longer an issue now that even everyday cars have grown to the size of Hummers.
The 928 was a tough, reliable car in its day. The engineering effort that went into it was off the scale. With the right level of care, there’s no reason to suppose it can’t continue to provide sterling service to an owner in 2023. It’s a sweet drive, especially in auto guise, and it can sound amazing with a suitable pipe fitted. Parts are not as expensive as you might think and model specialists like Loe Bank in Bury and Paul Anderson (928 Spares) in Stroud have superb reputations and will look after you. The prices for well-maintained and original S4s have been on the rise for a while but don’t be surprised if they go up even more. Most UK 928s will have had several owners but if you can find your way around the paperwork and you’re willing to take a chance on left-hand drive imports you might be able to nicely cared-for low-ownership cars that have come to the UK from abroad.
The most affordable S 4 on PH Classifieds at the time of writing was this privately-owned late ’91 auto in white at £15,995. The mileage of 160,000 looks scary but the car has had a full overhaul by Autofarm and the original 16-inch wheels are available as an option to the 18-inch 964 alloys currently fitted. Here’s a 72,000-mile 325hp sign-off model GT in Guards red with linen leather. It’s not been serviced for a couple of years but it looks bright enough for £27,495.
Top of the shop prize goes to this ’91 GT also in Guards Red with linen leather. It’s described as an auto but it’s actually a manual and the condition looks exactly as you’d expect from a 26,000-mile car. That condition is reflected in the price too: a fiver’s change from £65k. Not sure if that includes the Black Sabbath cassette.
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