The V8 engine in the SL500 is strong, smooth and quiet. Acceleration performance is rapid for a 4000-pound car with 300 horsepower, but not breathtaking. The SL500 is capable of accelerating from 0 to 60 mph in about 6.1 seconds. That’s quick, but not as quick as a Porsche 911 Carrera or Chevrolet Corvette. The SL500’s 5.0-liter V8 engine develops 302 horsepower. Peak torque of 339 pounds-feet is available from 2700 to 4250 rpm, and 295 pounds feet is on tap from just 2000 rpm. That flexibility is designed to give it quick response at all engine speeds.

The V8 engine in the SL 55 AMG is extremely strong, but it's also smooth and quiet. Acceleration performance is breathtaking for a 4200-pound car with 493 horsepower. The SL55 AMG is capable of accelerating from 0 to 60 mph in about 4.4 seconds. That's quicker than a Ferrari 550 Maranello, a 911 Carrera, or a Corvette. Peak torque of 516 pounds-feet is available from about 1800 rpm.

The SpeedShift five-speed automatic transmission in the SL55 and SL600 is superb, with nearly imperceptible shifts up or down. Pulling the selector toward the left causes the transmission to shift down to the next gear, or the driver can use the right (up) or left (down) shifter buttons on the steering wheel.

Automatic Body Control lets the SL corner with authority, even though the tires are smaller than those on a 911, Corvette, or Viper. A Sport switch lets the driver limit body roll even further, eliminating 90 percent of it, while still delivering a silky smooth, quiet ride.

The SL roadster is packed with electronic wizardry that works amazingly well: electronic throttle control, antilock braking with electronic brake force distribution, electronic traction control and electronic stability control. These systems have been added to other Mercedes-Benz products in recent years, but the SL breaks new ground in the form of the world's first fully electronic braking system. If it didn't do anything else well, and it most certainly does, the SL would have to go down in history for this development alone.

The SL's electronic braking system runs on very high pressure, but the pedal feels normal no matter how hard you stop, and the ABC suspension won't let the car take a nosedive. Drive on any mix of tarmac, gravel, mud, water, ice or snow and the onboard systems keep the car on the straight and narrow with very little driver input. After five or six hours of fast driving on challenging roads, this car will make you feel like one of the masters of the universe. It's that good. It doesn't have the gut-level appeal of a Viper, Corvette, or Porsche, but the SL is far more comfortable and luxurious than any of them.

While the pedal feels perfectly normal under all braking applications, the system works quicker and faster than ordinary hydraulic braking systems and can proportion braking effort to each of the four tires depending on traction and yaw conditions, working hand-in-hand with the ABS, traction and stability systems as well as the standard active suspension system which Mercedes calls Automatic Body Control (ABC). These electronic features mean that this SL will corner and brake faster and harder and flatter than any previous SL while providing a huge envelope of protection against driver error and changing traction conditions.