BMW M1 Buyers Guide

Three numbers identify an M1. The chassis number ends in the car's serial, between 4301001 and 4301460; the engine number has the form M88 followed by a number; and a road car also has its place in BMW's road-car series, its Serie number. The BMW M1 Register's public table lists every serial with its engine number, its colours, its dates at Italdesign, Baur and BMW, its category and its first delivery, so a car's numbers, colours and kind can all be checked against it; a car repainted from its first colour shows against the table's entry. The table is compiled and states no sources, so a difference from it is something to look into. It also shows nine engine numbers entered against two serials each: an engine number that appears elsewhere in the table does not on its own make a car false.

BMW Group Classic, the company's heritage arm, has issued a digital birth certificate from the BMW Group archive since early 2024. Its order form asks for the chassis, engine and gearbox (transmission) numbers and for proof of ownership, and BMW says the detail it gives varies with the model and the car's age. How many were made explains what the serial, Serie and engine numbers record.⁠source 1​source 3

A serial alone does not say what a car has been. The Register marks a run of serials PROCAR and two more "PROCAR Test", and the six at the end of the sequence are spare bodies, sent in February 1981 to BMW, to the dealer group AHG of Bielefeld, to Schnitzer and Heidegger, and two to Seeger & Hoffmann. The Procars were built outside BMW, by Project Four, Ron Dennis's firm at Woking, by Tom Walkinshaw at Kidlington and by Osella in Turin, and each went back to BMW to be tested and set up. Race results do not always settle which car was which: racingsportscars gives some entries as "or" between two serials, and among its Procar entries of 1980 is a serial the Register gives to a road car.⁠source 1​source 4​source 2

The engine is the M88 six, with Kugelfischer mechanical injection through six throttles, a dry sump with its own oil tank and Magneti-Marelli electronic ignition; the engine has the detail. It starts without ceremony: "there's no priming as it's all sorted by Kugelfischer-Bosh mechanical fuel injection", Heseltine found in 2008, and Bell's car "fires immediately, hot or cold"; idling in traffic and then accelerating, Walton found, "does not cause hiccups". On the winter drive he reported in April 1981, Walton saw an oil pressure of about 7 bar and the oil at 90 °C (194 °F), the water some 20 degrees cooler. No source read describes how the injection wears or how it is set up. A restorer's film shows the work on one car:

Iain Tyrrell found the cylinder that was misfiring by the temperature of each branch of the exhaust manifold, fitted new plugs ("these engines eat spark plugs if they're started and shunted round", he said) and new injection pipes from BMW, balanced the throttles and warmed the engine before driving the car, as he advises.

On the ZF gearbox, first gear sits on a dog-leg, left and back. A.H., in 1984, found the change from first to second the only awkward one, Bell found the shift "a mite clumsy" around town and "marvellously crisp" at full attack, and Walton learned to have the clutch right down before choosing reverse, "or an embarrassing grunt from the gearbox would result". The clutch, a hydraulic Fichtel & Sachs twin-plate of "comparatively small diameter" in Walton's words, is where the testers part company. Walton, in 1981, found it "tiresomely long in travel and consciously heavy to operate"; Heseltine, in 2008, did not:

Of the later drivers, Brenwin Naidu of TimesLIVE in 2016 and Shane O'Donoghue of completecar.ie in 2020 both found it heavy.

Under the body, 20 glass-fibre panels moulded by T.I.R. and bonded and riveted to the frame, is a lattice of rectangular steel tubes. Walton found the panels "quite heavy, durable", with nothing of "the glassfibre horrors" of other cars, while Motor Sport's report of BMW's racing plans in January 1979 expected bodywork repairs to be the Procars' biggest cost, the bodies being hard to repair. No source read describes rust in a road car's frame or cracks in its body.

A.H., driving hard in 1984, found "no obvious Achilles heel, such as overheating brakes or rising oil temperature". The car was set up on Pirelli P7s, and Walton's test car of 1981 ran on Goodyear NCTs of the same sizes. The steering has no power assistance: Walton found it light enough to park without help, and Bell, in 1997, found it "clumsy, stodgy, heavy" on manoeuvres. The battery and the fuses are in the front compartment, and the single large wiper, Walton found, could not keep the windscreen (windshield) clear of winter salt and slush.

Fuel consumption in the tests ran from about 17 litres per 100 km (16½ mpg, imperial) in Walton's hard driving to about 10 litres per 100 km (28 mpg, imperial) at a constant 121 km/h (75 mph) in Bell's. The two fuel tanks sit ahead of the rear axle, one on each side, each with its own filler on the flank. And Walton's car came with a warning from BMW "to keep the internal air ventilation vents open to counteract any danger of excessive pressure at high speed popping the door frames ajar".⁠source 5​source 6​source 7​source 8​source 9​source 4​source 10​source 11

The M1 was never officially imported into Britain, as Heseltine wrote, nor officially sold in the United States, where the US National Historic Vehicle Register says only a handful were privately imported. In April 1981 Walton told British readers who wanted one to "get hold of the leaflet Permanent Import of Motor Vehicles into great Britain" and to check their "Personal Import Status" with their vehicle licensing office. Britain had 20 first deliveries in the Register, BMW (GB) Ltd taking 13, and the United States three; how many more arrived later, no source read counts.⁠source 5​source 12​source 7​source 1

Some M1s became other cars. Schnitzer's Group 5 car of 1981 put a Kevlar body on a reinforced M1 chassis, a Group 4 one by Slickpix's account, and AHG, the BMW dealer group in Bielefeld, converted road cars into the AHG Studie, with Procar-style spoilers, sills (rocker panels) and wheel arches on BBS wheels in three pieces; a short series of them, auto motor und sport wrote in 2021, had been planned. In December 2024 BMW showed a 1981 M1 made into a one-off in Techno Violet by Ronnie Fieg, founder of the New York label Kith; the M1 Hommage tells that story.⁠source 9​source 13​source 14​source 1​source 15

BMW Group Classic's own workshop, at its Classic Center, looks after, repairs and restores classic BMWs, and its Classic Partners, certified regional workshops, take on servicing, standard repairs and appraisals, in BMW's description of its services. The restorer in the film above is Iain Tyrrell, of Tyrrell's Classic Workshop.

The firms the period sources name are the ones that built and prepared the cars. Project Four, Tom Walkinshaw's firm and Osella built the Procars, and Heidegger and Mader prepared engines for them beside BMW Motorsport; among the Group 5 teams, Sauber built and GS-Sport ran the Nürburgring winner of 1981, and Schnitzer built its own turbocharged car. The BMW M1 Register publishes its table of every serial.⁠source 3​source 4​source 16​source 1