2012 Mercedes-Benz SLK350 review: 2012 Mercedes-Benz SLK350

2012 Mercedes-Benz SLK350

Wayne Cunningham

Wayne Cunningham

Managing Editor / Roadshow

Wayne Cunningham reviews cars and writes about automotive technology for CNET's Roadshow. Prior to the automotive beat, he covered spyware, Web building technologies, and computer hardware. He began covering technology and the Web in 1994 as an editor of The Net magazine.

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2012 Mercedes-Benz SLK350

2012 Mercedes-Benz SLK350

The Good

A new direct-injection V-6 in the <b>2012 Mercedes-Benz SLK350</b> delivers plenty of power and good fuel economy. The retractable hard top comes down in 20 seconds. The stereo interface shows album cover art and the Harman Kardon audio system creates detailed sound.

The Bad

In sedate driving, the seven-speed automatic can shift uncomfortably hard. The exterior styling is not cohesive from front to back.

The Bottom Line

A fun, luxury roadster, the 2012 Mercedes-Benz SLK350 carries an excellent cabin tech suite and delivers aggressive performance, but those looking for a cruiser might find the SLK350 too much of a beast.

As a somewhat cute roadster, the SLK previously appealed to trophy wives and very successful hairdressers. But not anymore. The 2012 Mercedes-Benz SLK350 comes out with an aggressive look in front and an exhaust note that sends small woodland animals scurrying for the hills.

Vents in the hood, a big lower air intake, and the prominent Mercedes-Benz badge on the grille declare that the SLK350 has something to prove, a chip on its shoulder from too many years of Sunday driving. But the rear does not maintain the new style, instead showing curves similar to those of the BMW Z4, one of its chief competitors.

With its panoramic glass roof, the SLK350 has a very futuristic look from the rear, which is not at all stylistically cohesive with the front end. From the back, the car looks like a space pod, something that would be floating around the International Space Station in 10 years or so.

As a retractable hard top, the SLK350's roof is an entertaining bit of tech. As with most modern movable tops of this type, it is power-operated, doing a bit of origami on itself at the push of a button. It stacks up in the trunk or unfolds itself, protecting the cabin from wind and rain. As a gee-whiz option, Mercedes-Benz also offers an electroluminescent top that changes opacity depending on the severity of the sun.

Eco, Sport, and Manual
Like the car's new front-end looks, the engine helped me feel secure in my manhood as I got behind the wheel of this former chick car. The 3.5-liter V-6, now featuring direct injection, starts up with the sound of an angry tiger, then settles down to a clearly audible idle. This thick steering wheel has a flattened bottom and sculpted thumbholds above the spokes, a practical style for slaloms and S turns.

Deeply grooved thumb slots above the lateral spokes hint at the SLK350's sport driving capabilities.

Paddles on the wheel complement the shifter, both working through the seven gears of the automatic transmission. A button near the shifter takes the car from its default Eco mode to Sport, then to Manual. Each of these modes changes the gearbox programming. And while an automatic may discourage sport drivers, this one uses a lock-up clutch, eliminating torque converter slush and creating hard gear shifts.

The SLK350's default Eco mode is actually its standard drive mode, with Mercedes-Benz' clever use of the letter E reflecting its claim that its cars are very efficient and emit minimal CO2. Expect to see other cars in the Mercedes-Benz lineup adopt this nomenclature.

While driving the car in Eco mode at low speeds on city streets, I found the high-revving engine and gearbox led to some herky-jerky motion. Moderately stepping on the gas pedal initiated gear changes that threw me back and forth in the cabin. The SLK350 didn't always behave in this manner, but at certain speeds it delivered less than the luxury driving character promised by the Mercedes-Benz brand. I would never want Mercedes-Benz to go back to the torque converter gearbox, but maybe a little refinement of this one's programming would eliminate the jerks.

Getting into higher speeds, the SLK350 delivered the kind of performance I would expect from a tony roadster. The leather seats and Harman Kardon audio system made the cabin a pleasant place to sit while covering boring stretches of freeway, but the short wheelbase and excellent engine note had me thirsting for the tight turns of a mountain road.

Open-top driving down the coast in the SLK350 was a delight.

The cabin of the SLK350 is an enticing place, Mercedes-Benz having taken pains to make it suitable for open-top driving. The Air Scarf technology blew warm air from the base of the headrest around my neck, and heated seats handled any other challenge from the fall weather. Mercedes-Benz also tried to minimize turbulence in the cabin, which mostly seems to work with the help of a screen between the headrests.

Detailed audio
With the top down, the wind noise at anything over 40 mph is intolerable. After hearing the jet enginelike volume during a bit of freeway travel, I brought up the side windows, which diminished the sound considerably even with the top still down. And made it possible to hear music from the 11-speaker Harman Kardon audio system.

That many speakers may seem like overkill in a two-seater, but I had no complaints. Although hampered by external noise, during later testing with the top up I could hear an excellent degree of detail from this system. It managed to lift tones and instruments from complexly layered tracks that might get lost when played over an inferior system. The system could also handle cranked-up bass without a problem. In some ways, the reproduction is too detailed, as high notes can become piercing.

The screen for Bluetooth audio-streaming playback shows song title, artist, and album.

When going through the many audio sources from the stereo, I was really impressed to find that the Bluetooth streaming-audio interface managed to show song information when playing from a paired iPhone. Most systems don't show any information. iPod integration also worked well, and the system includes some internal hard-drive space for music.

What is really cool is that the interface shows album art whether used with an iPod or a simple USB drive. Thanks to the car's Gracenote database, it indexed the tracks from a USB drive so I could select music by album or artist, and also displayed cover art in the list of albums.

The Bluetooth phone system and navigation seemed largely unchanged from other recent Mercedes-Benz models. The phone system did what I would expect, downloading my contact list and making it available with voice command.

The navigation system, with maps stored on hard drive, is also very good. It shows traffic data, and uses it to route around problems. Lane guidance helps with complex freeway junctions. The maps show some 3D-rendered buildings in urban areas, but not so many as to crowd the screen. It also shows some topographic detail, but that didn't show up in the area where I eventually got to put it through its paces on mountain roads.

The weather forecast screen shows useful information and has nice graphic design.

Mercedes-Benz also has finally added some more connected features to its infotainment system. A little globe icon in the top menu strip leads to Sirius weather data, which showed current weather, a five-day forecast, and a weather map of the U.S. When I finally got this car onto some twisty mountain roads, the screen showed a cloudless day and a temperature just a little under 70, perfect driving weather.

Finding the power
The trick with most automatic transmissions that have a decent Sport mode is to let it know you want to drive fast. Pin the accelerator on the straight, brake hard before the corner, and give it plenty of gas on the turn exit. Doing this in the SLK350 with the transmission in its Sport mode, I had the engine holding above 4,000rpm, where it could take advantage of its 302 horsepower, which peaks at 6,500rpm.

The transmission held its gear after the turn, but longer straights led to an upshift. And when I let up on the throttle to a moderate one-quarter pedal, the car would let its engine speed drop with further upshifts, despite the Sport mode.

But using the drivetrain well gave the car plenty of power coming out of the turns. And the SLK350 was definitely built to handle. That short wheelbase meant nimble cornering and the steering was precise, and allowed quick turn-in. The car felt light, offering nearly the quick handling of a Mini Cooper.

Mercedes-Benz came up with a new direct-injection V-6 for the SLK350.

As I threw it through turn after turn, the suspension held the car down well, never letting it wallow, and the traction control light flickered here and there, but didn't interfere with the driving. The wide rear tires kept the back end from losing grip and the engine kept up its aggressive growl.

Touching the button for Manual mode, I found second and third gears maintained good engine speed on these corners. And the reaction time to shifts was near immediate. The paddles let me make quick up or down shifts, showing the advantages of Mercedes-Benz's refined automatic transmission.

But the lock-up clutch in the transmission and the direct-injection engine aid with more than messing around with fast cornering; the SLK350 can also manage decent fuel economy. The EPA ratings are 20 mpg city and 29 mpg highway, excellent for a V-6 making this much power.

In sum
The 2012 Mercedes-Benz SLK350 proved a little jerky at first, not a smooth cruiser in the city, but out on open roads it responded well to aggressive driving. I reveled in the growl of the engine and the tossable maneuverability of this little roadster, but could see becoming annoyed with its performance when dealing with day-to-day traffic.

However, the cabin appointments would go a long way toward making up for any rockiness in the driving quality. Although the cabin electronics interface takes a little getting used to, I've used it in enough cars to be comfortable with it. The navigation system looks good and the route guidance worked well. I particularly liked the quality and multitude of audio sources, along with the sound from the Harman Kardon system.

Tech specs
Model2012 Mercedes-Benz SLK350
Power trainDirect-injection 3.5-liter V-6, 7-speed automatic transmission
EPA fuel economy20 mpg city/29 mpg highway
Observed fuel economy21.7 mpg
NavigationOptional hard-drive-based with traffic data
Bluetooth phone supportStandard, with contact list download
Disc playerMP3-compatible 6-DVD changer
MP3 player supportiPod integration
Other digital audioBluetooth streaming audio, internal hard-drive storage, USB drive, SD card
Audio systemHarman Kardon 500-watt 11-speaker system
Driver aidsDrowsy-driving prevention, parking distance sensors
Base price$54,800
Price as tested$67,565
2012 Mercedes-Benz SLK350

2012 Mercedes-Benz SLK350

Score Breakdown

Design 7Features 8Performance 8


See full specs Trim levels SLK350Available Engine GasBody style Convertible