Porsche 928 Buyer's Guide
Porsche's V8 grand tourer is finally being taken seriously, and our four sold results (£9,000 to £28,125, median £21,884) show a market that now pays real money for the right specification while still letting automatic S4s go for less than a decent hot hatch. Manual cars and late variants lead; everything else follows at a distance.
Know your versions
One generation, eighteen years of steady escalation. The original 4.5-litre car (1977 onwards, 240hp) is the purest shape; the 928 S (from 1979, 300hp) and the 4.7-litre S2 added pace; the S4 of 1986–1991 brought the 5.0-litre 32-valve engine, 320hp and the revised nose and tail; the GT was the S4's stiffer, manual-only driver's version at 330hp; and the 5.4-litre GTS (1991–1995, 350hp) closed the line as the most developed and now most valuable of all. Our results map neatly onto this hierarchy: the two manual GTs made £27,456 (a 64,500-mile 1993 car) and £16,313, an early S made £28,125, and a 1989 S4 automatic brought just £9,000.
What to pay
Four sold results spanning £9,000 to £28,125 with a median of £21,884. The £9,000 S4 is the honest bottom of the market: automatic, needing nothing catastrophic but commanding no premium. The GT results (£16,313 and £27,456) show what condition and mileage do within one model. Live listings extend the picture upwards: a 1983 S2 automatic is guided at £9,000–£11,000, a 1994 GTS manual at £36,000–£45,000, and a Gemballa-bodied S4 carries a £50,000–£75,000 estimate with bidding at £31,903 as we write. In short: S4 automatics from £9,000, good manual GTs in the £16,313–£27,456 band our results define, GTS money starting where GT money stops.
What goes wrong
The service item that writes off cheap 928s is the timing belt and water pump, due roughly every four years regardless of mileage; no evidence, no purchase, because a failure wrecks the 32-valve engines. The torque tube that connects engine to transaxle wears its bearings (a rumble at speed), and on later automatics a failing thrust bearing arrangement can let the crank load up and destroy the engine; specialists check for it, general garages do not. Engine bay heat hardens the wiring loom on older cars, the elaborate electrics (windows, climate, instruments) fail piecemeal, and sunroofs and hatch seals leak. Bodywork is galvanised and generally good; it is the accumulated mechanical backlog that kills them, so a thick specialist file is worth more than paint.
Our view
The 928 is a genuine future classic with one condition: it must be bought serviced, not cheap. A manual GT around our £21,884 median, or a documented S4 towards £9,000 for the brave, delivers a 160mph V8 Porsche for E30-money, and the GTS estimates show where the whole market is heading. The parts and specialist network is strong enough to keep them alive indefinitely; the deferred-maintenance car at any price is the one that ruins you.
