Why twelve into eight makes this a BMW you can count on

Although based on a relaxing GT cruiser, the 850CSi had a very different personality when it emerged from BMW Motorsport in 1992

Words John-Joe Vollans Photography Chris Frosin


all it a BMW M8 in all but name. That’s the way to get your head around this rarest of production BMWs. With the 850CSi, the company took what was already a hugely attractive and capable machine – the 850i – and gave it more of everything.

The 8 Series in any form is an appealing machine. Its svelte styling instantly strikes the right balance of sporting appeal and elegance – something that the firm’s coupés have been getting right since the 1950s.

The 8 Series was the product of a company at its creative zenith. The late 1980s also saw the Munich firm finally taken seriously as a luxury brand. Mercedes-Benz had always been the yardstick against which all but the smallest BMWs were measured. With the E34 5 Series, E32 7 Series and the E31 8 Series, Munich finally had a range to take the fight to Stuttgart and win.

So, with more power, speed, aggression and greater driver involvement, is the 850CSi a desirable and enjoyable modern classic? We got into the driver’s seat of one of the 43 remaining UK cars to find out.


Sublime as the 8 Series was, its new-found refinement flew in the face of the Munich firm’s hard-won reputation for delivering razor sharp, driver-focused machinery. The 
8 Series was a comfortable GT cruiser first and foremost. Its V8, and even 
its range-topping V12, were under-stressed motors, lacking some of the fizz that BMW fans had come to expect. Those who wanted ‘the ultimate driving machine’ were left feeling a little let-down.

The answer, of course, was to hand the 8 Series over to the Motorsport division at Garching. Work started on an ‘M8’ early in 8 Series production, and in July 1993 a final design was approved. Unfortunately, it was too wild and expensive even for BMW at its prime to put into production.

The M8’s styling, lacking the wings of other contemporary 1990s performance icons, made do with deep sculpted side scoops just in front of the rear wheelarches. The front end was given extra intakes and a more pronounced front splitter. The engine gained new twin-cam cylinder heads with Vanos variable camshaft timing and was bored and stroked to just over six litres, giving 550bhp. The new exterior panels were mostly made from carbon-fibre, which helped towards an overall weight loss of over 200kg compared to the standard 850i.


During testing the car was reported to achieve 60mph in under five seconds and top out at over 180mph; some even claim it was capable of 200mph. Sadly, just one magnificent prototype was made before BMW top brass deemed it too savage and expensive. The global financial crisis of the early 1990s wasn’t helping 8 Series sales and the idea of a Ferrari-beating range-topper that cost over $100,000 wasn’t deemed to be a sensible move.

Once the decision to can it was made, there was still the hole at the top of the 8 Series line-up to address. That’s where our 850CSi enters the fray. This time the engine ‘only’ produced 380bhp. This was achieved with some new cam profiles, a displacement of 5.6 litres, forged internals and new intake and engine management set-ups. The 0-60mph sprint was now achieved in 5.9sec, with top speed limited to 155mph.

Other CSi additions included a manual six-speed transmission, suspension lowered by 20mm and stiffened, plus a limited-slip differential with its own oil cooler. Styling revisions were the very definition of subtle. There was a revised front air dam, reprofiled side skirts and a slightly altered rear diffuser – but crucially, even though these cars were built at Garching, they didn’t boast any exterior M badges. Only a small ‘Powered by M’ badge on the rocker cover gave any indication that this was something other than a normal 850i.


The 850CSi we borrowed for a few pulse-racing hours is for sale at BMW specialist Nick Johnson Motor Co (nickjohnsonmotorco.co.uk). Sitting on 71,000 miles and in immaculate condition with a full BMW dealer service history, it’s hard to find a purer example of this rarest of Munich coupés.

Approaching the 8 Series you’re struck right away by its sheer scale. It’s nearly five metres long and almost two metres wide, but low slung, at just 132cm tall. At a hefty 1975kg, this is certainly an imposing amount of steel, but that pales into insignificance because the beauty of this supercoupé simply blows you away. It evokes elements of 1960s American muscle cars as much as it does contemporary GTs from Aston Martin and Ferrari.

Once inside the cabin, it’s clear that this behemoth can only have come from BMW in the 1980s. The switchgear, materials and even the smell is so evocative of that era of excess. The bank of buttons on the centre console is somewhat overwhelming at first glance. Then you notice the subtle split between the onboard computer at the top, the stereo in the middle and heater controls towards the bottom. A subtle toggle for adjusting the dampers just to the right of the gearstick offers settings for ‘S’ and ‘K’ – sport and comfort respectively.


Turning the reassuringly chunky key a sound like a dentist’s drill greets you as the excitable starter motor whizzes the huge engine over. A deep baritone growl soon emits from behind the dashboard and there’s the slightest, barely perceptible rock through the seat as the huge unit catches and delivers its prodigious idle torque. Let’s get moving...

The Servotronic steering takes the effort out of manoeuvring at low speeds and gradually dampens out the sensitivity as you get up to higher figures. It works very well, despite the rumours to the contrary. It suits the character of this big GT perfectly and I’m happy to leave it in its default setting. The clutch requires a bit of effort to disengage and re-engage, but that’s hardly surprising considering the torque it’s expected to deal with. The brakes are firm and exceptionally responsive – surprisingly so, for the era in which the car was built. But it’s that engine that impresses the most.

Planting the throttle in such a luxurious machine feels somewhat churlish – but after you’ve done it once, that feeling quickly passes. When you’re pushing this CSi, it seems to shrink around you and change its character altogether into something much more akin to an M5. It’s never going to feel like an M3 on a B-road, but it’s far better through the bends than you would imagine. There’s very little body roll; and that damping, which at first seemed a little fidgety, settles down when you start leaning on each corner.

Getting out of corners, you’re aware of just how hard the traction control is working on the rear wheels. I turn it off once and realise instantly that it was a mistake. The rear end lights up with a halfway prod of the throttle pedal and that LSD allows you to collect it nicely. However, this is a big car and going sideways down country lanes is certainly not advisable!

On an open A-road the 850CSi reigns supreme. It’s up to and over the national speed limit before you can glance at the speedo and mutter an expletive. If this car can be considered a toned-down version of the M8, then we can see why BMW played it safe. This thing is still savagely fast and would happily keep pace with modern performance saloons with that propeller badge on their noses.


Lewis PlumbBMW, M8