I Drove The BMW M4 CS On The Track—And Came Away Conflicted

The M4 CS is durable enough to take the abuse, but it needs some modifications to be truly great.

Photo by: Tirth Patel

By: Chris Rosales

May 29, at 10:00am ET

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BMW M is having a bit of a renaissance; I’ve never seen a period in which M cars have been this desirable or ubiquitous at the average track day. Sure, they’ve always been popular, but since the last-gen cars got affordable and the current cars got all-wheel drive, an M car with a few mods has seemingly become the default choice—even though, who the hell would track a 4,000-pound sport sedan?

This conundrum is exactly why I borrowed the more hardcore BMW M4 CS and mobbed up to Buttonwillow Raceway Park in California’s Central Valley. I can’t walk three feet at a track day without running into another modern M car, so it’s time to figure out why people love these things.

And, to be frank, there are several really great reasons.

Photos by: Tirth Patel

Not The Same As Before

For one, the old reputation of BMW M cars being finicky, unreliable things is almost fully extinguished. Somehow, someway, BMW made an incredible change, almost overnight.

The modern, turbocharged cars have something of a sterling reputation in track circles. Many experienced track hands, my friends included, praise the reliability of the things endlessly, whether it's the excellent factory brakes, the well-sorted suspension, or even the seemingly bombproof S58 engine.

But maybe most importantly: these cars are fucking quick. Look at any major national time attack competition series right now. Nearly every podium and every win is something BMW engineered—including the A90 Toyota Supra. I’d argue there are just as many F80-generation BMW M3s and M4s making up those numbers, with the modern stuff catching up as resale values go down.

Photo by: Tirth Patel

What Is 'Competition Sport?'

This popularity is why a car like the M4 CS exists. CS stands for "Competition Sport"—not "Coupe Sport" or "Club Sport." Admittedly, it doesn’t stand for "Track Special" or "Track Ready," either. But CS, for as long as BMW has used the name, means elevated track performance in every sense.

In the case of this M4 CS (G82, for the nerds), that means quite a bit more for your steep $124,675 base price. Power is up by 20 over the M4 Competition xDrive for a total of 543 horsepower. More importantly, it loses 77 pounds with a CS-exclusive carbon fiber hood, center console, roof, seats, and carbon ceramic brakes.

The M4 also gets CS-specific suspension and transmission tuning to compensate for that weight loss and the stickier Michelin Pilot Sport Cup 2 tires. It also gets a bunch of CS aero bits—unique front grilles, lip, side skirts, rear spoiler, rear lower bumper garnishes, and yellow daytime running lights.

Photo by: Tirth Patel

Taking On Buttonwillow

Under the blazing sunlight of Buttonwillow Raceway, I did my pre-run track prep. BMW’s instructions were simple: Set tire pressures and go. But it’s always prudent to give the car a close look before any track session, and torque the wheels for good measure. The torque spec, by the way, is a huge 105 pound-feet.

Track conditions were clear and warm at about 84 degrees Fahrenheit. Track surface temperatures read at 101 degrees. Overall, a hot day for any car, most of all a 543-hp twin-turbo inline-six.

Yet, the cooling package of the M4 CS, and indeed any M4, is quite substantial. No less than six heat exchangers are packaged within the nose. There’s a main central radiator for engine coolant, flanked by two auxiliary side radiators that also flow coolant. A dedicated, flat-mounted oil cooler handles oil duties independently, while another heat exchanger for the water-to-air intercooler stacks atop the central radiator. The cooling stack is completed by a gearbox cooler for the ZF eight-speed automatic transmission.

Photo by: BMW

That is a large part of that aforementioned durability. Most cars don't have cooling figured out from the factory, even most from Germany. Sure, they can take a track session or two, but that's it. What the M4 CS did was nothing short of astonishing: It cooled down after I pushed harder around Buttonwillow.

While starting temperatures hovered around 210 degrees for both oil and coolant, after a hard session, coolant temperatures trended down toward 190 degrees, while the oil remained a resolute 240 degrees. Both temperatures are quite ideal for extended track use. Without a separate gearbox temperature readout, I couldn’t comment on behavior, but there were no odd hiccups.

What did overheat was the Cup 2 tires. I got them blazing hot in just three laps, with reported temperatures exceeding 200 degrees—effectively boiling for a street tire. And frankly, even when the tires were cooled down, and I was gentler on the throttle, I found very little pleasure in driving the CS around my home track.

What the M4 CS did was nothing short of astonishing: It cooled down after I pushed harder around Buttonwillow.

The M4 CS' handling balance was nothing short of doughy. Nothing felt connected or responsive. Even with all systems off, it refused to do anything but understeer and grind its tires off, a big reason for those tire temperatures. More frustrating was the lack of options. The CS didn’t want to be driven in any style except its style, and that just means relying on its systems.

Its front tires were so overwhelmed by the simple act of cornering that adding brake pressure to tuck the nose simply increased the understeer. And that’s if you were lucky enough not to trigger its intrusive anti-lock brakes that panic and immediately reduce yaw rate, causing more understeer. Rolling any speed at the apex is unwise and will result in a lot of waiting, waiting, waiting for rotation. Meanwhile, no information whatsoever travels up the steering column to the oddly thick steering wheel. At least, exits are incredible thanks to the xDrive.

But there was a lot of good beneath the surface, things that gave me confidence in the potential of the car. The dampers were incredible, absorbing Buttonwillow’s bumpy surface and curbing with one-and-done motions while also keeping the CS light on its feet during transitions. Even if it didn’t want to turn during the corner all that much, it sure loved transitioning from corner to corner.

And the twin-turbo six is nothing short of incredible, with gobs of low-end torque and rewarding top-end power. The eight-speed gearbox matched the vibe with lightning shifts. And, if you gave up on speed and wanted fun, turning the xDrive off and going full rear-drive only, the CS became quite the competent drift machine. Sure, I couldn’t initiate a graceful drift with the brakes, but it sure did a nice powerslide.

Driven significantly under the limit, it would then be slightly more responsive. But hard-edged track car, this is not. Though it did a solid laptime around Buttonwillow CW13: 1:58.64. For a hot day in a car that felt like it didn’t want to turn, I found it impressive. Yet the cheaper, lighter Honda Civic Type R did a 1:59.5–That car, however, overheated in mere laps.

Not The M You Want

What do you think?

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Even though it isn’t my favorite to drive, there is no denying the competence of the M4 CS. And to be frank, everybody modifies their track-bound Ms. It isn’t far from greatness; a set of wheels and stickier, track-specific tires would fix nearly all of my issues. It already has the braking, cooling, seats, and overall calibration to get the job done, which is more expensive than you think.

But it becomes a question of value. If you want all the special CS stuff and you’re a hardcore BMW nerd who will lightly modify the car, this is your move. If you want an exceptional dual-purpose street and track car that will take very little to sort out, I’d save the money and buy an M4 Competition (which has all of the same cooling and cheaper steel brakes) and some mods.