2017 Mercedes-AMG CLA45 4Matic

Mercedes-AMG’s CLA45 compact sedan may only work the door at Affalterbach’s internal-combustion madhouse. But with a transverse inline-four engine producing a bonkers 188 horsepower per liter, it makes for one helluva greeter. A host of recent updates have made the CLA45 4Matic—already a serious performer when it debuted for 2014—even stouter for 2017, albeit without much addressing of its underlying issues.

The Hornet’s Nest

With its scrappy attitude and raucous four-cylinder blat, the all-wheel-drive CLA45—and its GLA45 hatchback crossover twin—has always traded some polish for boost pressure. A twin-scroll turbocharger still pumps a hefty 26.1 psi into AMG’s hand-assembled 2.0-liter M133 mill. But the addition of a new exhaust camshaft and a retuned computer for 2016 have upped its output by 20 horsepower and 18 lb-ft of torque for heady totals of 375 and 350. Amplified by our example’s $650 AMG Performance exhaust system, the CLA45 buzzes through its rev range like a chainsaw—at up to 88 decibels under full duress—and emits a sharp brrapp on upshifts at anything more than half throttle.

A snappy, seven-speed dual-clutch automatic harnesses the engine’s output with deft control, readily serving up rev-matched downshifts in its more aggressive settings and offering precise actuation via shift paddles on the CLA’s steering wheel. The AMG-tuned transmission still can be a bit clunky at slower speeds—witness our test car’s rather pokey 5.3-second pull from 5 to 60 mph—but its quickness on the move does help counter the lag from the big turbo. Although the 45 generally operates as a front-driver, its standard 4Matic all-wheel-drive system can route up to 50 percent of the power to the rear axle when needed.

With its peak torque plateauing from 2250 to 5000 rpm and all 375 horses in attendance at 6000 revs, the CLA45’s power hits quick and hard as it accelerates to an electronically governed 155-mph top speed (or 167 mph if equipped like our test car). AMG’s launch-control system can be engaged in the sportier driving modes by stomping on the brake pedal, toggling the paddle shifters, and flooring the throttle, which holds the revs at about 3000 rpm as it produces the sound of firecrackers exploding from the 45’s exhaust pipes. Let go of the brake and the 3563-pound sedan blasts to 60 mph in 3.8 seconds and covers the quarter-mile in 12.3 at 113 mph—a solid 0.4 and 0.5 second (and 3 mph) quicker than before, and not far behind the last 503-hp Mercedes-AMG C63 S sedan we tested. That pace also puts the CLA45 slightly ahead of AMG’s tamer C43 sedan with its factory-built twin-turbo V-6, which needs 4.1 seconds to reach 60 mph and can do the quarter in 12.7 at 110 mph. We have yet to see how the CLA45’s primary rival, the 400-hp Audi RS3, fares at the test track, but we’ll be strapping our instruments to that car very soon.

Fancy Feet

The latest CLA45 handles more sharply when fitted with its optional mechanical limited-slip front differential that was added for 2016. Part of the $2800 AMG Dynamic Plus package, the bundle also includes the higher top-speed rating, a sport-tuned suspension with two-way driver-adjustable dampers, and a maximum-attack Race mode added to the car’s standard Comfort, Sport, and Sport+ drive settings. Our example rode on $850 19-inch alloy wheels in place of the stock 18s, and was shod with 235/35ZR-19 Dunlop SP Sport Maxx RT performance tires. Compared with the 2014 model we tested on similar Continental ContiSportContact 5P rubber, the new setup glued the CLA45 to the skidpad with a full 1.00 g of grip (up from 0.94 g), topping any AMG-fettled C-class and matching the 10Best Cars–winning BMW M2. The sticky Dunlops also helped the 13.8-inch front and 13.0-inch rear brakes bring this AMG to a halt from 70 mph in an impressive 150 feet with zero fade.

While the CLA45 will always default to safe understeer at its handling limit, partially thanks to 60.2 percent of its weight resting on its front axle, AMG’s revisions allow it to change direction more assertively and with smoother flow at extra-legal speeds. The body stays almost tabletop flat in bends, and the electrically assisted power steering twirls with precision and a modicum of feel. Our car also featured beautiful Recaro performance seats ($2250) with red piping that bear-hugged front-seat occupants with supportive side bolsters.

The big tradeoff for the 45’s sports-car-like performance is that you cannot turn off its rambunctiousness. The whole car thrums to the feisty four-banger’s pulse, and the AMG suspension is stiff and short in travel, feeling brittle even in the softer of its two damper settings. Although our high-strung test car bettered its 30-mpg EPA highway figure by 1 mpg on our 75-mph highway fuel-economy test, it averaged only 20 mpg during its two weeks with us—3 mpg less than its city estimate.

Blowing the Bank

The CLA’s swoopy, compact proportions don’t lend it Mercedes’s most handsome four-door coupe design, but a mild facelift for 2017 does align it better with newer Benzes. Subtle tweaks to the front and rear bumpers including tacky carbon-fiber aero canards let it slip through the air more efficiently, and there now are standard LED headlights. Along with $300 red brake calipers, our test car’s Designo Polar Silver Magno matte paint boosted its curbside presence and added $2500 to the price, but the rip-snorting exhaust note remains this AMG’s greatest tell.

Minor changes to the interior include revised trim finishes and an updated 8.0-inch central display controlled via a console-mounted rotary knob, but a quick scan still reveals some cost-cutting on materials. This car’s rear seat remains especially tight, with the sedan’s sloping roofline severely limiting headroom. And many basic conveniences cost extra, such as heated seats, proximity entry and push-button start, and Apple CarPlay and Android Auto connectivity. The CLA45’s standard black décor is prominently spiced with red accents, including the seatbelts (black belts are a no-cost option), contrast stitching, the bezels for the HVAC vents, and red-and-silver AMG Design graphics on the dashboard. Our example went a step further with the $1650 AMG Red Cut Exclusive package which adds black leather upholstery with more contrast stitching, ambient interior lighting, and top-stitched MB-Tex trim on the upper dash and door panels. But the overall effect remains that of a juvenile delinquent dressed for a court date.

Such customization highlights the CLA45’s greatest ailment: its not-insignificant $50,945 starting price is but $2050 below that of Mercedes-AMG’s classier and more comfortable C43 sedan. Factor in all of the aforementioned extras and $6650 worth of additional infotainment, driver-assistance, and convenience amenities, and our $69,095 test car cost nearly $3K more than a big-dog C63 sedan with a twin-turbo AMG V-8 producing 469 horsepower. Even in the AMG asylum, where Formula 1–engined road cars now roam the halls, that is crazy.

Specifications >

VEHICLE TYPE: front-engine, all-wheel-drive, 5-passenger, four-door sedan

PRICE AS TESTED: $69,095 (base price: $50,945)

ENGINE TYPE: turbocharged and intercooled DOHC 16-valve inline-4, aluminum block and head, direct fuel injection

Displacement: 122 cu in, 1991 cc
Power: 375 hp @ 6000 rpm
Torque: 350 lb-ft @ 2250 rpm

TRANSMISSION: 7-speed dual-clutch automatic with manual shifting mode

DIMENSIONS:
Wheelbase: 106.3 in
Length: 183.8 in
Width: 70.0 in Height: 55.7 in
Passenger volume: 80 cu ft
Trunk volume: 13 cu ft
Curb weight: 3563 lb

C/D TEST RESULTS:
Zero to 60 mph: 3.8 sec
Zero to 100 mph: 9.4 sec
Zero to 130 mph: 16.5 sec
Zero to 150 mph: 25.9 sec
Rolling start, 5–60 mph: 5.3 sec
Top gear, 30–50 mph: 2.9 sec
Top gear, 50–70 mph: 3.3 sec
Standing ¼-mile: 12.3 sec @ 113 mph
Top speed (governor limited, mfr’s est): 167 mph
Braking, 70–0 mph: 150 ft
Roadholding, 300-ft-dia skidpad: 1.00 g

C/D FUEL ECONOMY:
Observed: 20 mpg
75-mph highway driving: 31 mpg
Highway range: 450 miles

EPA FUEL ECONOMY:
Combined/city/highway: 26/23/30 mpg