When Mercedes-Benz announced the new CLA45 AMG every other car manufacturer with any plans to put out a small four-cylinder car were no doubt saddened by the announcement. Other brands just can’t compare to the 2014 Mercedes CLA45 AMG‘s 355 hp and 332 lb-ft of torque and the sexy inspired styling that is packed into the mini sedan. Even with it’s base price of $48,350, it will likely set the benchmark for small performance sedans in the future.
Unlike the previous generation of the Mercedes A-Class (not the new generation A-Class which we love!) which was seen as more of a Mercedes branded commuter car, the new CLA has a young and fresh design with sexy lines that make it fit in with the rest of the Mercedes family. The design of the CLS is what attracted AMG to the project add to that it’s driving ability and there was no question that the CLA needed an AMG variant.
AMG made the decision early on that sticking with a four-cylinder was the only option for the CLA AMG. But surprisingly, even though the architecture between the standard Mercedes and the AMG is similar, the two share very few parts. AMG uses a proprietary block, head, and most hardware, the turbo, which provides 26 pounds of boost, is larger than the standard unit and requires an AMG-specific water-to-air charge-cooler. Then you have the pistons and crank that are forged, with balancing and weight optimization that are made close to racing level. The end result is a four-cylinder that outputs 355 hp and 332 lb-ft of torque. But even though this will be the most powerful I-4 for sale in the U.S., their is so much more ot the CLA45 AMG than these numbers.
Thanks to careful and near-obsessive engineering, the guys at AMG have produced a turbocharged engine that can deliver 177.5 hp per liter and develops full torque from 2250 to 5000 rpm. Not only can it deliver a huge amount of torque on demand, it can deliver the exact amount of torque the driver requires. It’s common for high-strung turbocharged engines to supply torque in an all-or-nothing way, but this CLA45 engine delivers levels of throttle modulation and response that is more fitting of a naturally aspirated mill. Full-throttle acceleration opens up a valve in the exhaust, creating an loud roar that peaks at every shift.
The engine is connected to a seven-speed dual-clutch transmission developed along with Mercedes. Off the line, the transmission can be a little too aggressive and snatches the clutch a little too quickly, feeling like a manual transmission with a less-than-skilled driver on the right pedal. Once rolling, however, shifts are fast without being violent. On the roads around Hannover and the amazing Bilster Berg Race Track, the transmission never faltered. It offers three modes: Comfort, Sport, and Manual. Pulling either paddle in Comfort or Sport allows for Momentary Manual mode, which will hold a gear until the driver initiates a kick-down with the throttle pedal or an upshift is needed at the rev limiter. On the track, using Sport Mode plus Momentary Manual seemed to work best. Pulling a paddle to downshift going into tighter turns would get the car into the powerband and the computer seemed to pick upshift points just fine.
Those same tight corners showed the necessity of the CLA’s all-wheel-drive system. This is still a front-wheel-drive-based system, and you will never confuse it for anything else, but it is still quite capable. AMG claims the system is up to 25 percent lighter than similar systems. Instead of a Haldex power unit hanging off the back of the transaxle, a clutch pack has been located on the rear differential housing for better weight distribution. The system can transfer up to 50 percent of drive torque to the rear tires. It’s tied into the car’s ESP and also uses steering input, yaw, and throttle level to determine how and when to transfer power.
Although AMG feels that the CLA’s suspension is best in class, it wasn’t up to the performance level of the powertrain. Like the base car, the AMG CLA uses a McPherson strut front and multilink rear, but that’s where the similarities end. As you would expect, spring and damping rates are more aggressive, but AMG has also changed both static and kinematic geometry. The front spindles were designed with more static negative camber, but the lower ball joint pivot was lowered to add more kinematic camber and raise the roll axis. If you’ve been paying attention during the last couple of years, you will realize that suspension performance is all about bushings, and this car is no different. The durometer (a measure of hardness) of all the bushings is different from the standard car, and even the steering tie-rods feature stiffer bushings. The difference is immediately noticeable not only in the level and clarity of steering feel, but also in impacts on broken pavement. Impacts can be sharp in the AMG, though they stay short of harsh.
The standard wheel is an 18×8-inch split five-spoke design, while the optional 19×8-inch multi-spoke wheel is available in silver or dark grey. The 18-inch wheel uses a 235/40 tire, while the 19-inch uses a 235/35. Underneath those wheels are 4-piston calipers over 13.8-inch rotors in front and single-piston calipers over 13.0-inch rotors in the rear. HT: John via MotorTrend
