The strongest story of the 2015 Mercedes-Benz C-Class's upgrades comes from a focus on the mechanical side of things. The C Class sheds up to 200 pounds from the previous car's weight, while upgrading engines with two new models.
Engines are indeed completely different than for the outgoing C-Class, and across the lineup you’ll find both stronger acceleration and better fuel economy. On C300 models, a 2.0-liter four-cylinder makes 241 horsepower and 273 pound-feet of torque, while the C400 gets a turbocharged V-6 making 329 horsepower and 354 pound-feet.
The twin-turbo V-6 engine is potent, and feels strong in any gear or rpm range; it pulls willingly whether passing at 60 mph or accelerating from a stop. The engine's note, though muted, is pleasant, with a good balance of induction and exhaust sounds delicately penetrating the cabin.
To us, it’s a matter of quick or quicker. The C300 is plenty fast for most; it feels wonderful and whizzy in the way that the CLA45 does; the engine finds its boost almost instantly, and while it doesn’t build to a high-rev frenzy or crackle like in the CLA45, throughout the rev band it feels stronger than the outgoing V-6 in the C350. As for the C400, you might not notice the 88-hp and 81-lb-ft gap between these two engines unless you have your right foot buried; during normal part-throttle driving, both engines feel almost equally perky, surprisingly -- although the sound is quite different, of course.
For those craving even more power and quicker acceleration, the answer is the 2015 Mercedes-AMG C63 or C63 S, on sale in the U.S. in April, 2015. Both versions use a 4.0-liter twin-turbocharged V-8 engine; for the C63 it's rated at 469 horsepower and 479 pound-feet of torque, while the C63 S gets 503 horsepower and 516 pound-feet. The resulting acceleration is brisk, if not quite mental: the C63 will hit 60 mph in 4.0 seconds; the C63 S takes 3.9 seconds. Both are electronically limited to 155 mph.
Steering in the 2015 C-Class is electrically assisted; but it's one of the best systems available today among luxury cars. Its variable ratio is precise and accurate, delivering predictable results for a given steering input; and there's just a bit of real feedback from the road surface. It's also fairly quick in its ratio, requiring just about 2.2 turns lock-to-lock, making tight maneuvers, especially when parking, that much easier.
The AMG models offer improved steering feel, thanks to a re-engineered front end and AMG-tweaked steering assist. Adjustable dampers control ride quality, an electronic locking differential controls power application (and aids handling), and the whole setup feels much crisper, much more tied together, than the standard non-AMG C-Class range--and more than the competition from BMW.
Weight savings in the 2015 C-Class come from much more significant use of aluminum in the car's structure, up from 10 percent in the previous-generation C-Class to nearly 50 percent in the 2015 model--the chassis itself weighs 154 pounds less than its predecessor. Saving weight means saving fuel, but also improving dynamic performance.
The suspension the new chassis rides on is improved as well, still offering standard steel springs in its base configuration, but now available with the first air suspension system to be offered in the compact luxury segment. The continuously variable damping system can be adjusted through a range of settings including Comfort, Eco, Sport, and Sport+ modes, along with an Individual option that allows the driver to tweak the settings to their own preferences.
In practice, the Airmatic suspension yields a comfortable, smooth ride and, thanks to a progressive-rate tune on the air-spring system, surprisingly little total body roll at the limit. While that sounds good, it's a little disconcerting, keeping oddly flat in all but the tightest corners, and not allowing us to drive as smoothly and feel as ‘in touch’ with the car at times when we want it to momentarily play the role of sport sedan. And there’s no major improvement in ride quality or road noise.