It’s rare to find myself in possession of two new M cars, but when BMW sent over that CS, I had to see what your extra $40k (ish) gets you. So before it left, I did just that: let’s get the M3 Competition vs M4 CS and see what’s what.
Below are some questions I’ve compiled from readers, as well as a few of my own.
M3 Competition vs M4 CS: Suspension, tires and steering
The M4 CS’s biggest revisions probably come in the form of tires and suspension. I’ll explain:
Can you add the M Performance suspension to the M4 CS?
If you look at the photo above, you’ll see that a car with the MPS has slightly less wheel gap than a CS. BMW tells me that yes, you can technically install the M Performance suspension on the M4 CS, but they do not recommend it. The CS has unique shocks, springs, roll bars, front chassis brace, camber settings, traction control and software tuning to give it a much sharper chassis overall. To be blunt, it doesn’t need a set of lowering springs.
If you’re intent is to mod your G8X, I’d simply buy a regular one.
Are the wheels on the M4 CS special?
Not from a technical standpoint. They are forged aluminum, in the same 19 and 20-inch diameters as the Competition model. Though you can spec a more street friendly tire on the CS, the one I drove had Michelin Pilot Super Sports hugging those gold wheels.
Given that a tire is the only physical connection you have to the road, they are one of the most important decisions to make in terms of performance. Softer tires like the ones here wear much quicker, but given the CS’s overall performance potential, it’s worth it to spec this no-cost option.
Why does the steering feel so different?
The CS has unique steering software that adds heft and provides more feedback. However, I’d love to try a regular Competition on those Super Sport tires. Softer rubber is another way to improve steering feel, so it’s difficult to know where BMW’s chassis improvements end, and the tire’s begin.
M3 Competition vs M4 CS: Engine and transmission
It’s sometimes difficult to sometimes tell the difference between the S58 in an M2 (453 horsepower), and one in an older G80 (503). But the CS is more than a steroid injection.
How does the CS make more power? Can I do it to my own car?
Sure. The M4 CS has 543 horsepower, 20 more than an M3 Competition with xDrive, and 40 more than one without. It’s the most powerful inline-six from BMW that I’ve driven, nearly matching an F10 M5’s V-8.
There’s no black magic involved. BMW simply ups the boost and revises the engine management software. No special engine heads, pistons, rods, or additional cooling required. Go ahead and tune to your heart’s content.
Does the M4 CS sound any different?
The CS has a titanium muffler that saves about eight pounds, but can make the car sound more raspy. That’s often a byproduct of titanium mufflers.
If you’re in Sport Plus the car can boom a bit more than the Competition, but it’s still not nearly as loud as an aftermarket exhaust.
Is the transmission unique? What about xDrive?
The CS doesn’t get Porsche RS levels of changes like stiffer bushings. Again relying on software, BMW has given the car a unique feel with simple lines of code adjustments. The hardware all remains the same from an M3 Competition with xDrive.
I’ve looked into it, and for about $300, you can have someone upload the CS tuning for the steering and transmission. The only caveat – you can’t update the software, which means that if iDrive needs an update and you do it, you’ll lose the coding. It’s probably something I won’t do to my car, which amounts to baking a cake without many of the ingredients needed.
Also of note, I’d need the tune from an M4 CSL, because it’s rear-wheel drive like my M3. xDrive models can use the M4 CS stuff.
M3 Competition vs M4 CS: The cost
Can I turn my M3 into a CS?
Sure, but why wouldn’t you just buy one?
Let me give an example. That beautiful carbon fiber hood? $20,000 grand as a stand alone part from BMW (I asked my dealer), and that’s before painting it.
How about those yellow DRL headlights? BMW got wise to the act, and the LCI units are all sealed. You can crack em open, but my God man, why are you looking for problems?
Is the M4 CS worth the additional cost?
You can build an M4 Competition with xDrive, outfitted with just about everything:
- Carbon buckets
- Frozen paint
- Extended leather
- Carbon ceramic brakes
- Carbon package
Final price: $113,175. If you want an M4 CS, it starts at $123,500. Considering the extra power and all the chassis changes, $10k isn’t terrible. But if you want to add carbon ceramic brakes and Individual paint back in, you’re at $137,675.
For that price, you could wind up in a number of dedicated sports cars with two seats, like the Corvette Z06 or Cayman 718. But if you’re a G8X fan, all those small chassis changes have made perhaps the last, best M car with an ICE engine.
