The BMW M3 is a fantastic car. let's be honest, though; if you are looking for a two-door sports coupe, getting an M3 is a bit ... obvious, particularly when you consider what else is out there.
You don't even have to look outside the borders of Deutschland to find meaningful M3 competition. Cars like the Audi RS 5 and the Mercedes C63 AMG Edition 507 aren't just competitive with the iconic Bimmer; they are positively outstanding in their own right. But if you are going to drop $80,00 of your hard-earned dollars on a Teutonic power coupe, which one should you get? Worry not, Digital Trends is here to help.
Powertrains
Both the Audi and the Benz come packing some serious muscle. Although we're deep in days of turbos and supercharges, both cars derive their god-like power form of naturally aspirated V8s. These throwbacks to the heyday of muscle cars may be old-school, but they use technical witchcraft to put out stunning amounts of power.
Yes the 4.2-liter V8 in the RS 5 might have originated in 1991, but saying it's old fashioned is like saying Einstein is basically just an Australopithecus. This motor has evolved; and now it has more in common with the R8's V10 than the original 4.2. Thanks to its evolution, this Teutonic typhoon puts out 450 horsepower and 316 pound-feet of tire-shredding torque.
This stunning engine revs like a race car engine all the way north of 8000 rpm ... and sounds like an angry lion. But it also calms down when you want it to, which is nice when you are just trying to cruise home from work rather than give the old lady on the sidewalk a heart attack.
If the Audi's engine is impressive, though, the hand-built V8 in the C63 AMG 507 is a living legend, all the more so because it is about to be retired.
The V8 displaces a GTO-like 6.2 liters and while Audi might be happy with 450 hp, the AMG blows by with a Porsche-punching 507 hp. Even more telling is the difference in torque: Audi 316, Mercedes 450. I guess there is something to that old saying: no replacement for displacement.
Every explosion in the combustion chamber of this mighty V8 feels and sounds like the world coming to an end, but they just keep coming as you are pulled into another dimension on a wave of German firepower.
It is no knock on the awesome engine in the Audi to say that the Mercedes takes the cake in this category.
Performance
While these two cars engines may have more in common than you might expect, how they deliver their performance is as different as night and day.
The Mercedes C63 AMG 507's engine hints at just how it delivers its performance. With 507 horsepower in a car that is the size of a Honda Civic, everything happens at a savage pace. 0 to 60 is conquered in 3.8 seconds. Even that doesn't do justice to the sheer ferocity of the experience. The 507 will keep up this wild rate of acceleration all the way to 176 mph where it slams angrily into an electronic limiter. Limiter? Damn you Heinrich!
The Merc is no mere muscle car either, because on a track it handles like a dream ... albeit a scary one. With rear-wheel drive, this car is game for everything from controlled oversteer to drifting. However, if you want to get the most of the C63 AMG, you had better be damned good, because asking the rear wheels to put down that much power is difficult.
Fortunately, as with all Mercedes, the chassis feels solid like it is carved from granite. Unfortunately, so does the suspension. It will take you around corners fast, but it will also take important spinal ligaments and disks with it. That is okay for a day of track driving, but drive it on the street and you will be putting your massage therapist's kids through college.
The RS 5 is another thing all together. It's not quite as fast, with 0 to 60 times reported as low as 3.9 or as high as 4.5 seconds, depending on the tester. Though that says more about the difficulty of doing a full bore start in an AWD car than it does about the RS 5 in particular.
But if the C63 AMG 507 is carved from granite, then the Audi is carved from LeBron James's bones; it's powerful but agile. The car's response to the slightest input is simply sublime.
Also because it puts its power down through the world-famous quattro all-wheel drive system and one of the best sports transmissions ever made, a seven speed double clutch DSG, the performance is much more accessible more often.
The RS 5 is great on the track, but it is even better where you are actually going to drive it: on the road. The car corners like it is glued to the road, and accelerates from any rpm and any gear like a cheetah on meth. That grip gives you the confidence to take the car to the limit, where - depending on the dynamic setting - you get either some safe if slightly boring understeer or much more fun liftoff oversteer.
If you are a truly expert driver, or you plan on living at your local track, then by all means get the Mercedes. If you are something more closely approximating a human being, then the Audi RS 5 is going to be faster in the real world.
The Audi RS 5 takes this category for its everyday, usable power.
The real world
Chances are, if you are looking at getting one of these cars rather than a two-seater sports car like a Porsche Cayman or Corvette Stingray, you want your sports coupe do be at least vaguely practical. So what do these cars have to offer in the real world?
As already stated, the Mercedes is not a comfortable car. Fast, good looking, and distinctive? Yes. For people with low bone density? No. It does still have some practical qualities. though. It might be very, very expensive, a fully loaded example costs around $87,000, but it will retain its value. It's the last hurrah of the amazing 6.2-liter V8, which is being sent out to pasture. This makes the 507 an immediate collectors' item.
Collectability aside, the Audi just has much more to offer in the practical field. For starters, the ride is much better. You can commute in this car without wearing a backbrace. And with 16 mpg city and 23 highway, compared to 13 and 19 mpg for the Mercedes, you can not only skip a few gas stations you can also avoid the gas-guzzler tax. That helps keep the price down, a fully loaded RS 5 costs around $77,000 - a full ten grand less than the Mercedes.
For that money you also get slightly better features in the RS 5. For instance ,I prefer Audi's MMI system to Mercedes' COMAND.
The crown here goes to the Audi RS 5.
The Checkered Flag:
For all of their similarities the Audi and Mercedes offer very different experiences. The Mercedes is a stripped-down supercar masquerading as a sports coupe. There are very few cars that deliver this kind of performance feel, and, with that amazing engine, this is a very special vehicle.
I have massive respect for anyone who drives a Mercedes C63 AMG Edition 507. It is a statement car.
That being said, if you handed me the money I would gaze longingly at the Mercedes dealership and then happily walk over to Audi and buy the RS 5. Not only is this a car that does more things, it is also faster in the real world of rain, speed bumps, and herniated disks. Combine that with the fact that it is also a lot cheaper than the Mercedes and you have your winner: The badass from Ingolstadt, the Audi RS 5.
