2014 Mercedes-Benz CLA 45 AMG drive review

It's the novel Mercedes-Benz CLA compact sedan, all juiced up AMG style. If it's not exactly the AMG car for everyman, the CLA 45 will nonetheless move the brand within reach of more men and women than ever before. In the least flattering sense, you might call it the cheap AMG.

The CLA 45 represents several firsts for Mercedes and AMG. Most significantly it's the first AMG product created on a front-drive platform and the first with a four-cylinder engine.

It's no ordinary four-cylinder, to be sure. Mercedes calls the CLA 45's 2.0-liter, direct-injection turbo the most powerful four-cylinder ever manufactured in serial production, and we've found nothing to refute its claim.

The engine block is the same one used in the standard CLA250 with more sophisticated metallurgy, including AMG's Nanoslide plasma spray cylinder bores. The cylinder head starts with an entirely different casting, using more expansive coolant passages. Piezo injectors are crucial to the CLA 45's impressive output, as well as its emissions management and efficiency. These allow up to five separate fuel pulses per cycle -- usually in rapid succession during the compression stroke -- with multiple spark events to optimize horsepower or efficiency, depending on engine load and rpm.

No matter how much fuel AMG can force into the CLA 45's four cylinders, output still comes down to air in, air out. The flow starts at an intake channel with a cross-section larger than a softball. It continues through a single, twin-scroll turbocharger with a whopping 26 pounds of boost and an expansive air-to-liquid charge cooler, then spills out through 3-inch downpipes on the headers.

The net effect in the CLA 45 is 355 hp at 6000 rpm and 332 lb-feet of torque, starting at 2250 rpm and holding steady through 5,000. That divides to 178 hp and 166 lb-ft per liter of displacement. And still the CLA 45 engine meets the forthcoming Euro 6 emissions standard three years before mandate. It also delivers 34 mpg in the European fuel-economy cycle, though EPA ratings are pending.

The seven-speed Speedshift transaxle is similar in design and concept to the dual-clutch automatics in other AMG products, packaged in a case for transverse application. Gear ratios are higher across the board than those in the CLA250, with three overdrive gears on top, and the CLA 45's final drive ratio is nearly 50 percent lower.

In the CLA the 4Matic all-wheel-drive system is fairly simple, but effective. A power-takeoff on the transaxle constantly turns a drive shaft to the rear axle. When the management system detects front-wheel slip a multiplate clutch on the rear differential engages, without waiting for the drive shaft to spool up. Default torque delivery is 100 percent front. Depending on several variables, including vehicle speed; lateral and longitudinal acceleration; steering angle; friction differences between wheels and accelerator position, the rear differential will engage and power up the rear wheels -- typically dividing torque 50-50, but, for brief bursts on extreme low-friction surfaces, it can send all engine power to the rear.

Exactly how small is the CLA? Maybe not as small as you think. It's actually a couple inches longer and a fraction wider than the C-class sedan on a slightly shorter wheelbase. It's more than a foot longer than an Audi A3, 10 inches longer than a BMW 135is, and close in overall exterior dimensions to an Acura ILX. Yet it's lighter than the C250 and some of its smaller competitors, including the 135.

The CLA 45 won't offer the variable-damping suspension available on other AMG products. It uses the standard CLA's front strut/rear four-link layout with drastically altered tuning, with different bearings, bushings, shock and spring rates and thicker sway bars. It has larger brakes -- 13.8-inch x 1.2-inch rotors in front, 13.0 x 0.8 rear -- and AMG's three-stage stability control with all-off. It comes standard with 235/40 performance tires on 18-inch rims.

AMG finishes its CLA with larger, deep-gray intake ducts, a twin-blade grille, wider sills, a deeper rear bumper and twin chrome exhaust tips. Inside you'll find AMG instruments and data reporting, part leather sport seats with red belts, an AMG multifunction steering wheel with shift paddles and AMG door-sill trim.

The CLA 45 won't offer the vast array of options and customization choices typical of more expensive AMG products but it will offer more than the standard CLA. Upgrades include carbon-fiber trim packages inside and out, a performance seat upgrade with a broader range of adjustment, red brake calipers and 19-inch wheels. You can order one now for delivery this fall.

The idea with the AMG CLA is basically the same as with the standard CLA: Connect with younger buyers and cultivate loyalists who will purchase SL65s or SLSs when they grow older and richer. At a $48,375 base price including the $925 destination charge, the CLA 45 isn't exactly cheap. On the other hand its average transaction price is expected to be at least $20,000 less than the C63 AMG sedan, until now the bottom of the AMG pecking order in North America.

AMG CEO Ola Källenius understands there are risks in lowering the entry point for the AMG Club. In that context he believes it's not how the CLA 45 stacks up against AMG's twin-turbo V12s. The important measure is how the CLA 45 stacks up against anything of its size or in its direct competitive set. He figures most CLA 45 buyers will be conquests, purchasing their first Mercedes.

As for brand dilution, Källenius notes the average sale price for AMG products is higher than it's ever been.

“The large [AMG] dealers in Orange County and China are ecstatic about this car,” he says. “They see it as the gateway to Gen Y.”

How's it drive?

If you understand the CLA's underpinnings and have been fortunate enough to sample a range of AMG products, the CLA 45 drives about as you'd expect. It's pretty freaking fast. We're close to calling it faster than anything in its size class.

As a road car the CLA 45 can be perfectly civil and nearly docile. Its engine is tuned to deliver torque in giant, relatively short bursts, rather than howling along for extended stretches at 6200 rpm. It's quiet inside--almost surprisingly so. There's some wind around the A-pillars at 120, but the engine noise consists of just a soft drone. Only when you open the side windows does the deep exhaust bellow present itself, almost mimicking an AMG V8, and it's sweet listening to the shifts. The ride is anything but stiff, though we're sure the smooth roads in rural Germany didn't challenge it nearly as much as a Chicago freeway will.

The dual-clutch transmission approaches a conventional torque converter 'box's smoothness, distinguished only by a barely perceptible lurch as it shifts down through a coast-down stop. The efficiency mode -- it also engages the start/stop function -- works to get the CLA into the highest gear possible as soon as possible and it takes a deep push on the accelerator to get kickdown. We preferred the sport mode for casual driving even at the expense of some smoothness. Acceleration from a stop or a roll is basically 911 Carrera-grade. A Race Start launch-control mode is standard, though it's cumbersome to engage, with a specified sequence of button presses and then a double click on the shift paddles.

The difference between the standard CLA and the AMG version comes clearest on a racetrack, and Mercedes gladly offered the opportunity. They could have gotten away with a less-challenging venue. Theirs was Bilster-Berg -- a brand new, Hermann Tilke-designed track at a former military installation south of Hanover, destined for service as an automotive country club. The well-heeled volk who join here had better be reasonably competent drivers, too, or at least willing to repair their expensive exotic machinery. This is one of the more challenging tracks we've sampled in a while.

In short, Bilster-Berg is a mini Green Hell: 2.6 miles with 19 corners, many blind and some off-camber, 200 meters of elevation change with grades as steep as 26 percent, and 44 hill crests that unload the car.

The key, in the context of the CLA 45, is the unloading.

As is probably expected, it's much more confidence-inspiring on track than the standard CLA. The first thing you'll note is it's much more stable under hard braking, and then that it's faster in all circumstances. The CLA 45 still feels mostly like a front-drive car, though not because it's inclined to understeer grossly. It isn't so inclined. It feels like a front-drive car because when it unloads suddenly, as it does often at Bilster-Berg, the rear end gets light first and feels like it might come around -- like lift-throttle oversteer -- though it never did. The difference is, if the unloading isn't too sudden or extreme the CLA 45's rear wheels will power up and grip and settle the car back down, and enhance stability.

In sport mode the automatic works better than manual shifting on a scary new track. It competently selects appropriate gears so the driver can focus on finding the proper way around. The CLA bears up admirably when the driver comes up short. Carry too much speed toward an apex and it will suffer a hard stab on the brakes without fuss, and it won't push madly and completely lose momentum if you gas it too hard again on the other side. Partly because of its weight and dimensions, the CLA 45 is one of the most fling-able and forgiving AMG cars to date.

Back on the road, the CLA's swoopy, CLS-inspired shape (Mercedes makes no excuses) has its drawbacks. The view through the center mirror is narrow and the standard backup camera is almost a necessity.

The front seats are large and have plenty roomy for large bodies, but only the upgrade model has bolster adjustment to keep smaller torsos from sliding around. The rear seat? You'll get reasonably comfortable if you are 5'7” or shorter. If you're taller you'll have to cock your neck sideways or put your chin on your chest, or your head will hit the roof. And that's probably OK, because there is only enough trunk space for luggage for two on a four-day trip.

Some things that look like cost-saving in the standard CLA are less obvious in the AMG version, thanks to a generally higher level of standard equipment (though the wing antenna on the roof still isn't painted to match the car). The red-stitched, partial-leather interior upgrade on the CLA250 comes standard on the CLA 45, and the options make the AMG richer still.

The nut: The CLA 45 meets the AMG standard on a slightly different scale. It's comfortable and easy to live with through lazy cruising or profiling, pulse quickening when you hammer it and visually distinctive in all circumstances.

Do I want it?

If you're an AMG owner you might want it for a family member. But unless you have a green conscience, or want the improved fuel efficiency a smaller, lighter four-cylinder provides, we'd guess you'll prefer what you have now. If you've always wanted a genuine AMG-crafted Benz, the CLA 45 moves you about $20,000 closer to your prize, and you won't be disappointed.

What about the AMG CEO's standard -- best in class, not best in brand? With the BMW 1 Series M gone and the still-pending arrival of Audi's promised S3, we're not sure how to define the class. If it includes the Subaru WRX STi Limited -- given Mercedes' target buyer, it could -- the STi saves about 10 large. If the class includes the Audi S4, the choice gets tough.

Best to leave it here: For now, the CLS 45 AMG 4Matic might be a class of one.

2014 Mercedes-Benz CLA 45 AMG 4MATIC

Price: $48,375

Available: November 2013

Layout: Five-passenger, front-engine, all-wheel-drive sedan

Drivetrain: transverse 2.0-liter turbocharged inline four, 355 hp @ 6,000 rpm, 332 lb-ft from 2,250 rpm; seven-speed dual-clutch automatic transaxle

Curb Weight: 3,494 lbs

Performance: 0-60 mph, 4.5. sec; 155 mph top speed (manufacturer), 34.5 mpg (converted from EU liters/100km cycle)