New Car Reviews

First Drive: Mercedes-Benz A45 AMG Prototype

Mercedes-Benz will likely charge into the American-market compact-luxury party in 2014, several years tardy but with no shortage of enthusiasm. The incursion kicks off with the swoopy CLA-class sedan and will eventually include a sub-GLK crossover and an electrified B-class. The company’s U.S. stewards are also considering the A-class hatchback as a fourth small offering, but the car on these pages is significant even if Americans never have a chance to buy one. This A45 AMG prototype packs the same hardware that will power the CLA45 AMG sedan that arrives in U.S. dealerships in 2014.

We could hardly have picked a worse day for our first encounter with the A-class on steroids. From the start, the rain is pouring down on the scantily disguised, white A45 AMG, which returned only this morning from the torture chamber known as the Nordschleife. R&D chief Tobias Moers slides his short and wiry frame behind the squared-off steering wheel, pulls the red seatbelt tight, adjusts the mirrors, and hits the start button. From the passenger seat, I look over his right shoulder to see that the speedometer readout expires at 320 kph (199 mph) and the tach is redlined at 6200 rpm. The rest of the dashboard is hidden by a coarsely cut piece of camouflage. Even at idle speed, the 2.0-liter turbo four-cylinder sounds like no other A-class powerplant. As we pull out of the factory, the direct-injected unit emits a hungry growl that is duly amplified by a sound tube that connects the engine bay to the center stack.

Moers takes no time at all to find the limit of adhesion as I grope for the nonexistent grab handle, eyes wide open, mouth O-shaped, feet firmly planted against the firewall. As we time-warp through Germany’s green landscape, Moers talks about his pet project. “After years of dealing with rear-wheel-drive cars, the A-class was something totally different, something I did not look forward to at all in the beginning. Five doors, a gutless four-cylinder engine, terminal understeer — you can imagine the thoughts that crossed my mind. But I soon realized that this was a unique opportunity to rewrite the rules, to set new standards and eclipse the competition. From day one, I wanted this car to better the BMW 1-Series M coupe.”

Such potent competition spurred Moers to pump up the four-cylinder’s output to extreme levels: 350 hp and 332 lb-ft of torque. Code-named M133, the AMG engine is a modified version of the unit fitted to the A250 Sport, but apart from the 1991-cc displacement and the cylinder block, almost every part is new. There are now two radiators instead of one, the intercooler and the variable-vane turbocharger are larger, and the reengineered exhaust boasts four chrome tips as well as an optional full-volume mode. Although the numbers aren’t yet final, the AMG car is expected to accelerate to 62 mph in 4.6 seconds, and the electronically limited top speed of 155 mph can be stretched to 175 mph with an optional performance package.

The most significant game changer in the new A-class is its specially tuned 4Matic four-wheel-drive system. In the A45, it channels 60 percent of the twist action to the rear wheels, thereby reducing torque steer and understeer through slow first- or second-gear bends. This rear-wheel bias is particularly obvious with stability control off, when power oversteer can be induced quite easily, at least on drenched blacktop. Unlike the BMW 1-series M, which assumes sideways antics at the mere mention of the word “corner,” the A45 handles in a more sophisticated and diversified manner. “Controllability is the word I was looking for,” says Moers, dialing in just enough lock to complete a very subtle four-wheel drift.

Also new are tauter springs, firmer fixed-rate dampers, meatier antiroll bars, Brembo brakes, a wider track, and more substantial 235/35YR-19 tires. The A45 is equipped with a unique sport steering system based on the steering of lesser A-class models but with firmer bushings. The reinforced seven-speed dual-clutch automatic is masterminded by a reprogrammed black box, which ensures faster shift times and more dynamic shift patterns.

“We have done a lot of work to make this car more drivable than its competitors,” states Moers as he swings the prototype back toward Affalterbach, the wipers still on full speed and the passenger’s blood pressure still on alert. “Although the definitive setup is balanced and safe, you still get an amazing depth of feedback and information with the full sensation of speed.” This rare fluency of motion is evident from the passenger seat. The A45 AMG is not only very fast, it also is a remarkably interactive companion. Instead of fighting the driver, the road, and the laws of physics, the most desirable A-class knows more about pace and poise than many self-appointed sports cars. If Mercedes does indeed decide to bring the A-class to the United States, it would be smart to start with this version. After all, speed trumps size.

The Specs
On sale:
Price: $50,000 (est.)
Engine: 2.0L turbo I-4, 350 hp, 332 lb-ft
Drive: 4-wheel
Fuel Mileage: 19/28 mpg (est.)

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