1986 BMW M5 E28 vs. 1992 BMW M5 3.8 E34
We got the rare opportunity to sample pristine examples of the E28 and E34 M5 back-to-back, and what an experience it was.
Words SHANE O’ DONOGHUE
THE GENERATION GAME
The E28 M5 and its E34 successor are two classic icons – we see how they compare.
There’s no doubt that the new BMW M5 (the F90) is a formidable creation, putting all five of its predecessors to shame in terms of any measurable metric you can come up with. But even so, among car nuts, there’s an often-irrational affection for older vehicles that regularly overshadows their enthusiasm for the new metal.
Hence, it’s a bit of a risk to bring a new car’s predecessors along to its launch and then let the attendees loose. However, with such a rich vein of heritage defining the very essence of the M5 nameplate, perhaps BMW didn’t see it as a gamble at all but a way to reinforce the legacy of its iconic sports saloon.
With all six generations lined up (and our need to test the new car already sated), our gaze naturally fell on the origin of the species, the E28 model, so we grabbed its key without hesitation (yes, an actual key, which has to be turned in the door lock to open the car!).
BMW Motorsport was founded in 1972 to focus – as the name suggests – on the company’s racing cars. It eventually became involved with the road cars, too, at the request of particularly enthusiastic buyers, culminating in the creation of the M535i in 1980. And while you could argue a case for calling it the true origin of the species, the ‘M5’ badge wasn’t seen until five years later, when BMW Motorsport whipped the covers off the E28 M5 at the Amsterdam Motor Show.
The path to that unveiling undoubtedly helped set the template for the M5 brand, as it started with a special 3.5-litre inline six-cylinder petrol engine, codenamed M88, developed by BMW Motorsport originally for the mid-engined BMW M1 E26 sports car (which only existed in roadgoing format, don’t forget, to homologate the vehicle for racing).
The straight-six was then employed in the M635i before finding its home in the new M5. The free-breathing, high-revving, four-valves-per- cylinder combustion chamber design was carried over, as were the six individual throttle valves. However, the E26 M1’s dry-sump lubrication system was replaced by a more conventional wet sump, and the M5 got its own design of pistons and connecting rods.
On top of that, the M5 benefitted from more modern Bosch Motronic fuel injection and engine management. The result was 286hp at 6500rpm, plus 251lb ft of torque at 4500rpm; enough to propel the relatively lightweight saloon (BMW quotes 1430kg unladen) to 62mph from rest in a respectable 6.5 seconds. Then on to a top speed of 152mph. When the M5 was launched with such figures, it was declared to be the fastest production saloon in the world – and they’re not to be sniffed at today, either.
However, the ravages of time, and the endless increase in power outputs (and hence our familiarity with higher, accessible performance), haven’t been kind to this car. Today, it feels slower than the performance figures would suggest, even though there’s a good deal less than 100,000 miles on this example’s odometer. Nonetheless, the straight-six sounds great – gravelly and pure of voice through its offset exhaust outlets. It pulls cleanly, too, eager to pile on the revs despite its age. And though the thin-rimmed and well-worn steering wheel isn’t particularly nice to hold, it connects your hands with the front wheels in a more intimate manner than most modern cars manage.
This car is all about delicacy, and you get the most from it by treating it with a softness of touch. Visually, that’s conveyed by the spindly column stalks and almost brittle-feeling switchgear, while the less-than-slick five-speed gearbox demands all your attention and rev-matching skill to smoothly make swift progress down a challenging road. And it doesn’t take long to realise that, while you’re not going to break any speed records, you are enjoying the drive immensely, and engaging with the car. The chassis feels short of wheelbase, giving it distinct agility, and it really flows with the road, helped by great visibility past the slender and upright windscreen pillars.
The E28 M5 uses the same suspension layout as the regular 5 Series of the day, with McPherson struts up front and a semi-trailing arm design at the back, though the geometry was tweaked, and many individual components were upgraded by BMW Motorsport, depending on the market, including the dampers, springs and anti-roll bars.
There’s evidence that BMW changed the specification of these throughout the lifecycle of the car, too. All E28 M5s featured new, 300mm front brake discs, replacing the 284mm items from the M535i E28 and anti-lock brakes as standard. At the rear was a mechanical limited-slip differential, which helps reduce scrabble of the inside tyre when exiting tight corners but, in truth, it takes commitment and a decent amount of momentum to unstick the rear tyres and, even then, there’s not enough torque available to hold a slide for very long. It’s just not that sort of car. And anyway, who’d drive a classic like that…?
This 1986 example, from the BMW Classic collection, has been fitted with the optional M Technic aerodynamic package, which includes a rubber boot spoiler and a relatively subtle body kit featuring ribbed extensions to the side sills and bumpers – plus de-chromed side mouldings. As this package was also fitted to the E28 M535i, it doesn’t make the M5 instantly identifiable as that, though the front and rear ‘M5’ badges are unambiguous.
In fact, BMW Motorsport originally launched the M5 with almost no adornment, aiming to give buyers a wolf in sheep’s clothing, as it were. Most used the modest, forged alloy wheels pictured here, as shared with various other BMWs, though later examples came with sportier-looking, cross-spoke wheels measuring 16” in diameter.
Production, largely done by hand in Germany (with a few exceptions), ended in 1987, with some 2241 cars sold. That, incidentally, caused problems in America, where buyers were told that just 500 M5s would be made. In 1991, a class-action lawsuit was filed against BMW North America, and it settled the case by giving the buyers a $4000 voucher (a little over £2000 at the time) towards buying or leasing a new BMW. That blip aside, it’s clear something special had been created by BMW Motorsport, and the division went from strength to strength.
Although the second generation of the M5, based on the E34 5 Series, was still hand-made by BMW Motorsport, it was already beginning to take shape as a proper standalone model, whereas the original had the feel of an afterwork project done by the engineers. Indeed, the E34 M5, launched in 1988, was the last to have a link to an engine originally developed by BMW Motorsport for racing. Bore and stroke were increased so the straight-six became a 3.6-litre unit producing 315hp at first (called the S38B36), though capacity was upped to 3.8 litres in 1992, as the S38B38, increasing power output to 340hp in most markets. Notably, a catalytic converter was fitted to all variants of this model, while only the North American and Japanese versions of its predecessor had one.
The increase in engine capacity to 3.8 litres was accompanied by significant upgrades elsewhere in the engine, including lighter valves and pistons, larger throttle bodies, a higher compression ratio (10.5:1), new Bosch engine management, an individual ignition coil for each cylinder, new inlet and exhaust manifolds and the adoption of a dual-mass flywheel. The latter was designed to smooth out the engine’s idle, but it dampens response a tad, too.
Nonetheless, behind the wheel, this engine instantly feels far lustier than its predecessor we drove earlier in the day on the same piece of road. It’s friskier for sure, despite a considerable increase in mass, and this low-mileage example (there are fewer than 15,000 miles on the clock) feels fresh. Driven back-to-back, it’s hard to believe that there’s only 0.6 seconds difference in the official 0-62mph times.
This model took a clear leap forward in modernity, too, in line with the regular E34 5 Series. Its interior is much more luxurious and closer in concept to the M5 of today than you’d expect, thanks to the increase in electronics and technology. The four-spoke steering wheel is a little bland to look at, but it feels good to hold, and the E34’s power steering is more consistent than the E28’s.
The five-speed manual gearbox has a more precise shift action, too, along with perfectly placed pedals for a little gratuitous heel-and-toeing. And this car encourages such behaviour, with the unmistakable straight-six howl from under the bonnet combined with a level of agility that belies its extra weight and increased dimensions. It looks like (and is) a bigger car, but it never feels it from behind the wheel.
The E34 M5 launched with self-levelling rear suspension, with the overall layout the same as the E28’s, though with the new E34 5 Series setup. The M5, however, was 20mm lower than the regular model, riding on springs that were 25% stiffer. Naturally, the damping was altered, and the anti-roll bars thickened. For the 1992 model year, Adaptive M Suspension was introduced, which was a BMW Motorsport development of the E32 7 Series’ Electronic Damping Control adaptive system.
If buyers opted for the Nürburgring Package (as fitted to this test car), they got a two-position switch for this to choose between ‘normal’ or ‘sport’ damping and, even in the latter mode, this car rides with really impressive suppleness, married to decent body control. The package also included ZF Servotronic, speed-sensitive power steering, thicker rear anti-roll bars and wider 17” alloy wheels fitted with 255/40 ZR rear tyres. Also in 1992, BMW introduced the M5 Touring, accompanied by the slogan “The new BMW M5 now has significant competition.”
Regardless of which body style buyers chose, the E34 M5 retained the understated approach to design of its predecessor, though with a fraction more uniqueness to help identify it as the flagship. Highlights included the early ‘M System I’ turbine-style 17” alloys (the pictured car is sitting on M System II wheels) and subtle, lower body panels. The Daytona violet metallic paint of this test car disguises one of the few easy ways to identify the rear of an E34 M5 – a black panel between the rear lights holding the registration plate.
In a dark colour and with the M5 badge deleted from the rear, it wouldn’t be easy, even for an M-car anorak, to say for sure that they’re looking at the real deal. The purity of line and unadorned bodywork looks lithe and pretty today next to the complex curves and sharp lines of the modern equivalents.
Signalling its popularity, the E34 M5 remained in production until 1995, resulting in a remarkable 12,000 or so sales (900 of them in the Touring body style), and it remains just as popular to this day.
The E28 M5 is light on its feet and hangs on tenaciously
The E34 received comprehensively uprated suspension, and it shows
E28’s cabin has a certain charm E34’s interior feels a lot more modern and luxurious. The E28 M5 was an incredibly subtle machine.
E28 M5’s M88 made 286hp. 3.8-litre S38 in the E34 developed 340hp
MODEL E28 M5 (1986) / E34 M5 3.8 (1992)
- ENGINE Six-cylinder inline
- CAPACITY 3453cc / 3795cc
- GEARBOX Five-speed manual / Six-speed manual
- MAX POWER 286hp @ 6500rpm / 340hp @ 6900rpm
- 0-62MPH 6.5 seconds / 5.9 seconds
- TOP SPEED 152mph / 155mph
- WEIGHT (DIN) 1430kg / 1670kg
“THE STRAIGHT-SIX SOUNDS GREAT – GRAVELLY AND PURE OF VOICE THROUGH ITS OFFSET EXHAUST OUTLETS”