The audio quality of the stock system, though full, suffered from shrill highs. We played a variety of music through the system and were generally impressed with the frequency range we could hear, and the good separation that made bass, mid, and treble notes distinct. But as we turned the volume up, the highs became unbearable as the speakers turned what should have been a clear high vocal into an eardrum-piercing note. The system handled bass-heavy tracks without rattle, but the Logic7 system seems a necessary upgrade.
The SLK350 also comes with standard Bluetooth hands-free cell phone integration. We were initially frustrated to find we couldn't pair a Samsung phone with the system. Checking the Mercedes-Benz Web site, we found that the car is compatible with most Nokia and Motorola phones, along with various BlackBerry models and the iPhone. We successfully paired it with a BlackBerry and found the call quality to be good. The car let us easily import our phonebook contacts, and kept a record of recent calls. And we finally had a use for the keypad Mercedes-Benz puts on the dashboard of most of its models.
Under the hood
The SLK-class is available in three versions marked by their engines, from the 3-liter V-6 SLK300 to the 5.5-liter V-8 SLK55 AMG. The 2009 Mercedes-Benz SLK350 is powered by a 3.5-liter V-6 that Mercedes-Benz squeezes 300 horsepower at 6,500rpm and 265 foot-pounds of torque at 4,900rpm out of. Although the SLK350 is a small car, the horses don't translate to rocket ship power. It moves fast and smooth, but we didn't get the blast in the back we expected. During one drive on a two-lane highway we started to pass a line of cars, but when oncoming traffic appeared, the SLK350 didn't have the guts to keep us confident in the maneuver. We did make it to the front of the line, but had to consider slotting back into the line before our intended spot.
The engine feeds its power to the wheels through a seven-speed automatic transmission that keeps shifts very smooth. Through a little technical wizardry, the transmission exerts a little throttle when it downshifts to keep the engine speed matched to the gear. Our car had the standard seven-speed transmission--a sport version is available, complete with paddle shifters. The automatic transmission can be put into Sport mode at the push of a button, or you can manually shift by pushing the shifter from side-to-side. The manual shifts were tighter than a normal slushbox, but they didn't feel exceptionally sharp. We concluded that our test car, lacking the Sport package, was tuned more for a fun, luxury ride than hard-core driving.
The steering communicated this feeling as well. It is responsive when you want it, but it isn't twitchy, letting you drive without having to constantly adjust. Because of the car's small size, we felt we could throw it around readily, and it seemed perfectly amenable. The back end would slip a little in hard cornering, but not in a way that wasn't correctable. Mercedes-Benz dials back the tech in the steering a little, relying on a mechanical system for its variable power steering.
Mileage with the SLK350's engine is an EPA-rated 18 mpg city and 26 mpg highway. We came in around the middle of that range, at 21.3 mpg for a mix of city, highway, and freeway driving. Mercedes-Benz derived more efficiency from the engine by raising its redline and increasing the compression. Emissions ratings weren't available at the time of our review.
The 2009 Mercedes-Benz SLK350 goes for a base price of $50,825. Our test car included the $2,950 Premium package and the $990 Heating package, which brings in the Air Scarf system, taking the total to $54,765. Given our choice, we would also add the Multimedia package, which includes the Logic7 audio system and navigation, for $2,980. When shopping for a roadster in this price range, we would also take a long look at the Audi TT, a car with better handling due to its Quattro all-wheel-drive system.
For the SLK350's cabin tech rating, we have to take a little bit on faith, as our test car didn't have all the options available. Fortunately, we've seen the newer navigation system in the C300 and have heard the Logic7 in several Mercedes-Benz models, letting us extrapolate a little into the SLK350. With the Multimedia package, the car would exhibit some impressive tech, although nothing over the top. As for performance tech, we like the seven-speed automatic transmission and the refinements Mercedes-Benz made to the engine. It's not a barn burner, but the car is well balanced and fun to drive. But it is a lot of money for a car that can only carry two people and minimal luggage with the top down.