Mercedes-Benz CLS-Class Performance
The 2012 Mercedes-Benz CLS sees some major changes under the hood. The previous model’s 5.5-liter V8 has been replaced with a smaller, 4.6-liter twin-turbo V8 that Mercedes says is more powerful and more fuel efficient. Test drivers are unanimously impressed with the new mill. They say that it provides ample power with no turbo lag, and is paired well to the CLS550’s seven-speed automatic transmission. Power is sent to the rear wheels, but an all-wheel drive version of the CLS is expected in the near future.
Keeping all four wheels planted is Mercedes’ Airmatic adjustable suspension. Test drivers say that the CLS handles well for a large car, and that its tight turning radius makes it more maneuverable than you might think. Still, some reviewers say that the electronic power steering system feels too light at times, and that while the brakes do an excellent job of stopping the CLS, a few test drivers say the pedal feels slightly mushy.
If you like the CLS550’s sharp design and attractive interior, but want a car with better performance, check out the CLS63 AMG, which is reviewed separately.
- "From a pure driving standpoint, the car is responsive in its handling, powerful enough to be highly entertaining and comfortable and quiet." -- AutoWeek
- "Over the road, the CLS550 provides something similar to the E550 experience - which is to say, biased toward luxury rather than sport." -- Car and Driver
- "You'd never guess the 2012 Mercedes-Benz CLS550 grew heavier by the way it takes to the road. We sampled the CLS in the hills and dales of central Italy and, simply put, it drives beautifully." -- Edmunds
- "How does 402 horsepower and 443 pound-feet of torque from a twin-turbo 4.6-liter V-8 - in the cooking-grade CLS550 - grab you? We decided to give her a test drive, and we weren't disappointed." -- Motor Trend
- "Sure, we'd like a little more communication through the wheel and from the slightly squishy brake pedal, but in the realm of a jaw-droppingly stylish sedan, the CLS continues to stand in a class of its own." -- Autoblog
Acceleration and Power
The 2012 CLS550 doesn’t just boast all new styling; there are significant changes under the hood as well. The previous model’s 5.5-liter V8 has been replaced with a 4.6-liter twin-turbo V8 that generates 402 horsepower, which is 20 more than the 2011 model. In addition to more power, it’s also more fuel efficient. According to the EPA, the 2012 Mercedes-Benz CLS550 gets 17 mpg in the city and 25 mpg on the highway, which is a notable improvement compared with the 2011 model’s 14/21 mpg city/highway fuel economy.
Reviewers give the new engine high marks, saying that there’s virtually no turbo lag and plenty of power. They also love the CLS550’s seven-speed automatic transmission with paddle shifters, which performs comfortably in Normal drive mode, and livens up nicely in the CLS550’s more-aggressive Sport mode.
- "While the CLS is not a true sports car, there's enough performance from the twin-turbo V8 to get, and keep, your attention." -- AutoWeek
- "The engine sounds good, but it’s very muted, and under full throttle the V-8 growl fades beneath a blanket of turbo whoosh. The power delivery is sensational, though, with no perceptible turbo lag." -- Car and Driver
- "CLS550's V8 is strong in any situation. For the most part, power delivery is smooth thanks to an alert transmission. Some turbo lag is evident from a stop, but it's minimal." -- Consumer Guide
- "Lag in the new engine (engine code M278) is a nonissue so there's an immediate response when you flex your ankle. The plentiful torque is delivered seamlessly even from low revs." -- Edmunds
- "Our ride showed up in a sexy black dress and wowed us with a zero-to-60-second sprint of just 4.3 seconds, same as the old AMG." -- Motor Trend
- "The CLS550' seven-speed - even in Sport mode - is a more refined gearbox than the Speedshift MCT setup fitted to the CLS63. Shifts might not be neck-snappingly quick, but they're smooth and measured, and coupled with the nearly lagless turbo 4.6-liter, high-speed freeway runs and backroad blasts are effortlessly dispatched without sacrificing engagement." -- Autoblog
Handling and Braking
The automotive press is generally in agreement that the 2012 CLS handles with surprising agility. Some reviewers don’t think there’s much of a difference between the adjustable air suspension’s Normal and Sport modes. But the CLS550 earns high marks for its tight turning radius, which makes the big car more maneuverable than you might think. Its electronic power steering lightens up at low speeds to easy parking maneuvers and firms up at higher speeds to provide a sportier feel. Still, some reviewers comment that the CLS’ steering is a little too light and that the brake pedal has a slightly mushy feel.
- "The electronic power steering is among the very best we've experienced from any manufacturer, with a direct response not found on recent M-B sedans. The feel tightens up when pushing the car a bit harder into corners while giving a nice, easy response for city driving." -- AutoWeek
- “CLS is more agile than you'd expect from a car this size. A fairly tight turning radius makes it very maneuverable. Both models suffer little body lean in fast corners. The steering has a tight, firm, and direct feel.” -- Consumer Guide
- "The air suspension and continuously variable damping combine for a plush highway ride. Ultimately, however, it lacks a convincing degree of athleticism: Though precise and linear, the new electric power steering provides far more feedback than does the chassis, which is pretty inert." -- Car and Driver
- "There's tidy handling and an absorbent ride from the air suspension and variable dampers, and the new electrically assisted steering is pretty transparent, if a bit too light at low speeds. It loads up naturally, however, and the mechanically variable ratio that quickens as you add lock is a real boon in helping the CLS drive smaller than it is." -- Edmunds
- "With all the zigging and zagging, we got to know the CLS's new electromechanical power steering (Mercedes calls it a world first for the segment), which provided a direct, balanced feel in every situation we encountered, high speed or low." -- Motor Trend
- "Body roll, dive and squat are all present but minimal, and the 14.2-inch front brakes with four-pot calipers (12.6-inch in the rear with single-pot stoppers) partnered with the standard 18-inch all-season rubber (sized 255/40 R18 on 8.5 x 18.0 wheels in front and 285/35 R18 on 9.5 x 18.0 out back) make deceleration a competent and composed affair." -- Autoblog