We're flat-out on Germany's Sachsenring race track in the new Mercedes SLS AMG, chassis number 00045, a mildly camouflaged pre-production model. Ahead is an SL65 AMG Black Series--twin-turbo V-12, 670 hp, 738 lb-ft of torque--driven by Tobias Moers, head of AMG's r&d division, seasoned race instructor and today's pace-setter. Filling his mirrors, our red gullwing keeps pushing harder and harder, even though its normally aspirated 6.2-liter V-8 is rated at a comparably modest 571 hp and 479 lb-ft. The Sachsenring has plenty of slow corners, lots of climbs and descents, two long straights and two very fast and very blind fourth-gear bends.

As our session progresses, this track is becoming a nightmare for the wide, fat SL, and dreamland for the light and nimble SLS. Despite the Black Series car's four more cylinders, 100 extra hp and 259 lb-ft of added torque, it's punished by its 551-lb weight penalty. The SLS not only uses a significantly lighter double-wishbone aluminium suspension, it also boasts a featherweight spaceframe body which tips the scales at a mere 531 lbs. Perhaps even more significant is the weight distribution. In contrast to the nose-heavy SL, the new gullwing places only 48 percent of its mass on the front axle and 52 percent on the driven wheels.

In this match, the Black Series SL doesn't stand a chance. It understeers early, and after only ten laps it has practically run out of front tires. The momentum gained on the straights can never compensate the speed lost on the approach to and through the infield.

The SLS is a totally different animal. It is 49 inches low and 76 inches wide, with cab-backward proportions that emphasize the front-mid-engine layout. The boxy light-alloy skin is draped over a long, 105-inch wheelbase. The gullwing doors open at a large 70-degree angle, but even when fully deployed, the maximum clearance is a scalp-threatening 5 feet, so that short people can still reach the inner grab handles from their seats. The power-operated buckets, which feature lightweight magnesium backrests, are comfortable and supportive.