M5 (E28)

An M1 Engine in Search of a Body The M88 was designed for the mid-engined M1 of 1978, a homologation car built in tiny numbers for a racing category that evaporated around it. BMW Motorsport was left with an expensive twenty-four-valve straight-six and no volume car to put it in. The M88/3 that reached the M5 was the road-adapted answer: still 3,453 cc, still twin camshafts, four valves per cylinder and six individual throttle butterflies, but converted from the M1's dry sump to a wet sump, given Bosch Motronic management and run at 10.5:1 compression. The M635CSi had the engine first; the M5 put it into a four-door bodyshell that advertised nothing beyond a deeper front airdam, a small boot spoiler and blacked-out brightwork.

Hand Assembly at Preussenstrasse The M5 was not built on a production line. BMW Motorsport GmbH assembled the cars by hand at its Preussenstrasse premises in Munich, moving to Daimlerstrasse in Garching around the summer of 1986 as volumes grew. That method set the shape of everything that followed. Output was low - Motor Sport reported in October 1986 that only about 250 cars a year were planned - the options list was short, and by the time the North American allocation was being built the practical answer to colour choice was black.

Amsterdam, 1985, and the Fastest Saloon in the World Production began at the end of 1984 and the car was shown publicly at the Amsterdam Motor Show in February 1985. It was, at that point, the fastest production saloon in the world, and cost accordingly: 86,000 Deutschmarks in Germany, 31,295 pounds in Britain. Motor Sport's road test of October 1986 recorded 0-60 mph in 6.3 seconds, 0-100 mph in 17.1 seconds, 151 mph and 19.7 mpg, and noted approvingly that the car looked like just another 5-series. That combination - a supercar's pace in a shape that drew no attention at all - is the whole of the super-saloon idea, and the E28 M5 is where it starts.

The Catalyst Cars: America, Japan and the S38 Markets requiring emissions equipment could not take the M88/3, so BMW Motorsport produced the S38B35: same capacity, compression dropped to 9.8:1, a simplified exhaust manifold, shorter camshaft duration, a catalytic converter and, usefully for surviving cars, a dual-row chain in place of the M88/3's single row. Quoted output falls between 252 and 256 hp depending on which source is doing the quoting. North American production ran from November 1986 to November 1987 and sold as a single 1988 model year at $46,500, every car black, almost every interior Natur tan. BMW had indicated around 500 would come; roughly 1,340 did, and some early buyers who had paid for exclusivity went to law about it. Japan took thirty cars in early 1987.

Rosslyn, and the End of the Run Right-hand-drive European production began in March 1986 and accounted for 187 cars. South Africa was the exception to everything else: 96 M5s were assembled from CKD kits at BMW's Rosslyn plant, the only assembly point for the model outside Germany, and specified more richly than any of them, with Highline Nappa leather normally reserved for the 6- and 7-Series, M-Technic bodywork and cross-spoke 16-inch wheels. German assembly finished in November 1987 by the market tables, though Wikipedia and Motor1 both run production to June 1988; Rosslyn was still building into late 1988. The E34 M5 that replaced it was built in larger numbers, on a line, with a bigger engine - and every generation since has been measured against the first.

The M88/3's single-row timing chain is the defining risk of a European car; Classic Trader records chains breaking well before the 100,000-mile replacement interval, and the North American and Japanese S38B35 with its dual-row chain is the more durable arrangement in this one respect. On both engines the plastic chain guides and the tensioner deteriorate with age and should be inspected whenever the front of the engine is open. Mechanical valve clearances need checking at roughly 30,000-mile intervals, and neglect runs from rough running to valvetrain damage. Six individual throttle bodies must be synchronised or the car idles unevenly and feels flat in the mid-range; perished vacuum hoses produce the same symptoms and are cheaper to cure. Oil leaks appear first at the cam cover gasket, then the sump and main seals. Cooling is the quiet danger on a high-mileage car: a failed water pump or thermostat can overheat an engine that is expensive to rebuild and whose parts are hard to find. Elsewhere the faults are those of a 1980s E28 - corrosion in the footwells, boot floor, sills and window surrounds, tired bushes and dampers producing wandering and an unsettled rear, cracked dashboards, worn leather, failing instrument-cluster electronics and an ABS system that costs real money to service. Gearbox synchros rarely fail outright, but clutch replacement is a substantial bill.

Establish which engine the car has and whether it is the one it left the factory with. An M88/3 car and an S38B35 car are different propositions, and conversion of a US car to European specification is common enough that European-looking bumpers prove nothing. Written proof of timing chain replacement is the most valuable document on an M88/3 car: the single-row chain can let go before the nominal 100,000-mile interval and the consequences are terminal. Ask when the valve clearances were last set: they are shim-and-bucket, need doing on a schedule, and neglect shows up first as poor running and later as damage. A clean idle and a strong mid-range both depend on six throttle butterflies being in balance, so an uneven idle is a synchronisation question before it is anything more expensive. On the body, look at footwells, boot floor, sills and the corners of the front and rear window frames, and treat quick MOT-season patching as evidence of what is behind it. Inside, cracked dashboards, tired leather and a failing service-interval cluster are usual rather than remarkable, but trim is slow and costly to source, and the ABS costly to put right. Records of real, continuous use are worth more than a low odometer reading with nothing behind it.

As of August 2026, classic.com records a BMW M5 (E28) market benchmark of $58,257 against an average sale of $52,618, on a rising trend, with tracked results running from $8,000 for a 1988 project car in January 2023 to $183,000 for a 9,000-mile 1988 car in March 2026. The highest public result recorded anywhere is more recent still: $195,810 on Hagerty Marketplace on 2 April 2026 for a single-owner, all-original 9,800-mile US car from the Enthusiast Auto Group collection carrying roughly $91,000 of 2020-2025 refurbishment. The Classic Valuer's aggregate for the model since 2020 gives a median of 42,987 pounds - the figure a 112,667-mile US-delivered car converted to European specification made at Collecting Cars on 27 April 2025 - against a low of 6,984 pounds and a high of 116,334 pounds. Collecting Cars' own 2026 guidance places undocumented projects at 25,000 to 40,000 pounds, sound higher-mileage drivers at 45,000 to 60,000, and exceptional original cars at 65,000 to 80,000. RM Sotheby's sold a US-specification 1988 car from the Youngtimer Collection at Essen in 2019 for a published 57,500 euros; the catalogue does not separate hammer from buyer's premium. South African cars trade in their own market, quoted locally in 2026 at 450,000 to 750,000 rand and above 900,000 rand for the best.