Will the BMW M4 CSL be worthy of the moniker?

Road Cars

BMW CSLs are a rare thing – the German marque's approach with its modified M4 looks conservative but, as Andrew Frankel writes, M4 cars have defied expectations before


BMW CSLs are a rare thing – can the latest live up to the name?


Thanks to the first past the post system, minority governments are exceedingly rare in this country. In the last half century there have been just three elections where the party with the most seats has nevertheless failed to secure an overall majority in the House of Commons (one Labour, one Conservative). But over the same period of time, they have actually been half as common again as BMWs wearing the fabled CSL badge.

There have been just two in the last 50 years: the original Coupe Sport Leichtbau, based on the E9 coupe and designed as an homologation special with which to contest the European Touring Car Championship, and the E46-based M3 CSL of 2003. But now there is another, a variant of the current M4 of which just 1000 will be built, with 100 coming to the UK. Priced almost exactly £50,000 ahead of the car from which it is derived, the £128,820 M4 CSL promises to be a very special car indeed.

But making promises and keeping them are very different things, so we should take a closer look at just the third car judged worthy of this most special name plate.

It exists to celebrate the foundation of BMW’s Motorsport department, whose then 25 employees toiled to turn that old E9 into a successful racing car. The first M-badged road car was another homologation special, the M1 produced from 1978-81 which was followed by the M535i, M635CSI, M5 and original M3. The history of M since then is altogether too large to delay us here.

So let’s jump instead to the present day where we find the M4 CSL presenting as conspicuously track-focused machine. With 542bhp from its mildly modified B58 straight six twin turbo engine, it is also the most powerful M-car ever built on a 2, 3 or 4-series platform.


M4 CSL has set fastest Nürburgring lap for a production BMW, but 7min 20sec is hardly a headline time in 2022


But CSLs are meant to be light, hence the ‘L’ in their names, to which end BMW has shorn 100kg from the kerbweight of the car, measures including but not limited to the addition of ceramic brakes and lightened alloy wheels (21kg), deleted rear seats (21kg), carbon fibre front seats (24kg), reduced sound insulation (15kg) and a part titanium exhaust (4kg). The remainder comes from a CFRP bonnet, lighter carpets and weight shorn from the ventilation system, front grille and rear lights.

The chassis has been lowered by 8mm and comes with its own spring rates, roll bars, damper settings as well as a front strut brace and rigidly mounted rear subframe. And if you’re still not sure of BMW’s intended purpose for this car, be advised it is fitted with Michelin Cup 2R tyres as standard, the most extreme road legal tyre made by the acknowledged masters of track day rubber.

So there it is and I can’t wait to get my hands on one. But until I do, perhaps I might still sound a note of caution because, cynical old hack that I am, I’m not going to be persuaded that this car deserves to be called a CSL just because of the badge on its back. And there are one or two things that concern me about it.

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Strangely enough, none of them is its power output despite it being only a modest increase of a little more than seven per cent. The weight reduction is another matter. One hundred kilos seems a very precise figure, which would unlikely to be arrived at by a team striving to make the car as light as possible. On the contrary it seems they were given a target which, once achieved, was deemed to be ‘enough’. And 100kg in a car that even thereafter still weighs 1625kg is a reduction of just over six per cent, also known as, ‘not very much’. The car may be lighter, but BMW cannot credibly describe it as light. It’s less even than that shorn from the E36 M3 CSL nearly twenty years ago, which started off as a far lighter car to begin with.

It could have been made lighter still, and doubtless more engaging to drive by the replacement of its eight speed automatic gearbox with a six speed manual. And by ‘automatic’ I don’t mean a whipcrack double clutch transmission, but a conventional torque converter auto. Which doesn’t sound very CSL either. And then there’s the outright pace, and while I am not one to dwell unduly on Nürburgring times, its 7min 20sec lap just isn’t that fast these days, especially for a car wearing Cup 2Rs.

Inevitably comparisons will be drawn between it and the Porsche 911 GT3 which, while less powerful, is so much lighter (by either just over or just under 200kg depending on whether you choose the manual or double clutch gearbox, because it makes both), it actually has a considerably better power to weight ratio. As well as that manual gearbox option, a normally aspirated engine, and a Nürburgring time that places it over 20 seconds further down the road after just one lap.


Our writer thinks BMW can go much further with M4 weight-loss


Then again, what does any of this actually prove? Not much. M cars have a habit of defying expectation and the new CSL may be the same. The M5 CS seemed like a complete waste of money until I drove one, while the M2 Competition looked like it would be merely mildly entertaining, yet turned out to be one of best driver’s cars BMW has produced in recent times. By contrast the previous generation M4 GTS looked promising in the extreme on paper yet I didn’t much like it on the track and absolutely hated it on the road.

And if you’re still pondering that price, remember that exclusivity will be a large component: Porsche has somehow created the illusion that its GT products are rare creatures, but in fact they churn out as many as their production slots allow. Buy an M4 CSL and it will be rarer than any GT3 of the recent and not so recent past.

Even so, I do wish BMW would do a proper Leichtbau. Forget increasing power or adding aero packages or track focussed tyres, but see just how light it can make an M4: light panels throughout, thin glass, decimated equipment list, simplified loom, full titanium exhaust, carbon wheels and so on and on, down to the smallest detail. And a manual gearbox. I bet they could lose another 100kg without too much trouble and, if so, they should just keep going. The result would become a cult car overnight and would sell in small volumes at a significantly higher price than that already asked for this new CSL. What’s more, people would still be talking about it 20 years from now, providing an enduring and ongoing value to the BMW brand. Will people still be talking about the new CSL 20 or even 50 years from now? I’ll have a better idea once I’ve driven it.