We had no problem finding reviews that extensively covered the high-performance SL63; however, only a few reviewers had spent significant time with the SL550 or SL600.
Car and Driver noted that the V-12 versions of the 2009 Mercedes-Benz SL come with a five-speed automatic rather than a seven-speed but had no complaints about the five-speed’s performance. Each of the transmissions includes Touch Shift manual control and paddle shifters, along with comfort, sport, and manual modes.
Reviewers of the SL550 complimented its responsive V-8, while the more powerful SL600 didn’t get quite as many good words because, explained Car and Driver, turbo lag could sometimes be an issue when driving on roads with tight switchbacks and wherever there was a need to quickly get on and off the throttle. Car and Driver estimated a 3.6-second time to 60 mph for the SL600 and 4.9 seconds for the SL550.
The big SLs generally handle much better than might be expected for a vehicle that weighs up to 4,555 pounds, depending on the trim, thanks in part to the second-generation Active Body Control (ABC) system. “ABC does a remarkable job of keeping body roll completely snuffed while soaking up all but the most torrid impacts,” said Car and Driver. ABC includes a Sport mode that tightens handling up even more and can lower ride height at higher speeds.
Big four-channel anti-lock brakes keep the 2009 Mercedes-Benz SL’s speed in check. Car and Driver called them “completely fade resistant," but said that they “felt a touch artificial as the hypersensitive anti-lock system constantly fiddled with the brake pressure at each wheel,” especially on rough surfaces. The SL600 gets larger brakes to match the power, but several reviewers reported that they seemed taxed on mountain grades. “On mountainous portions of our test route, and despite a liberal use of engine compression braking, we still noticed an excessive smell of brake materials on the SL600,” reported Leftlanenews.com.
Driving impressions were decidedly different regarding the high-performance SL63—indicating that these are the models to favor if you’re so inclined to wear racing footwear. Motor Trend pointed out the “uncommon combination of massive low-end pull and willingness to rev” of the SL63’s 518-hp, 6.2-liter V-8, and Motive described it as delivering “the heaviest, most satisfying V-8 kind of power there is, tractable at the low end and manic at the top.”
The 2009 Mercedes-Benz SL AMG cars feature a completely different, more aggressive MCT SpeedShift transmission, which can function as an automatic transmission but in its performance mode will match revs during downshifts and shift in cooperation with the braking system. The gearbox now has four different modes altogether for high-performance or comfort-oriented driving, along with a so-called Race Start mode, which is the equivalent of, Motive says, “essentially brake torquing the living hell out of this superpriced ingot of German metal.”
More aggressive suspension and chassis tuning for the AMG models up the 2009 Mercedes-Benz SL ’s performance potential. Motor Trend thought that a “more than adequate power and chassis balance lend it a nimbleness belying the curb weight,” while Motive said, “The SL63 feels heavy here, but in a good way.” Later, the reviewer commended its grip and described it as “impossible to provoke.” Braking was nothing to complain about here: more powerful six-piston calipers “confidently scrub off the SL63's easily accrued speed,” according to Road & Track, which also said that the “steering feels considerably more direct than in standard SLs.”
Although TheCarConnection.com hasn’t yet driven the 2009 Mercedes-Benz SL, our prior experience comparing the SL550 with the SL55 AMG, which the SL63 replaces, confirmed that the differences are way more than skin deep; with slightly different tuning to the steering, brakes, and transmission, it’s not simply a case of a more powerful engine stuffed in. The SL550—and SL600 especially—aren’t the kind of cars that beg to be driven hard, but the AMGs are.