2020 Mercedes-Benz SL-Class Performance

A choice of two high-powered engines gives the Mercedes-Benz SL-Class roadster extremely high performance figures. Rear-wheel drive is the only option for the Merc, while rivals like the BMW 8 Series offer an all-wheel drivetrain variant. With the standard 362-hp V6 engine, the SL 450 has plenty of zip. It isn't quite as quick as the all-wheel-drive BMW convertible, which reaches 60 mph in just 4.6 seconds. However, the Merc can complete the 0-60 mph sprint in 4.9 seconds, according to the manufacturer, as opposed to rear-wheel-drive BMW's 5.0 seconds.

The SL 550 gets the more powerful twin-turbocharged V8, which develops 449 hp and 516 lb-ft, allowing it to shave off some of that sprint time, reaching 60 mph in just 4.3 seconds. This is slower than the BMW M850i which reaches 60 in under four seconds, although this particular 8 Series has the benefit of 523 hp and all-wheel-drive. Still, the SL Roadster is plenty quick for a convertible that emphasizes luxury over athleticism.

The base engine on the Mercedes SL-Class is a 3.0-liter turbocharged V6 that directs 362 hp and 369 lb-ft to the rear wheels only. A 9G-Tronic nine-speed automatic transmission smoothly rows the gears for the roadster during acceleration, but it isn't quite as smooth on the downshift. This powertrain is more than strong enough to lug the nearly two-ton convertible around town or hurtle it down the highway, and passing at speed is a simple task for the capable V6.

If you need more power, you can tack on an extra two cylinders with the 4.7-liter bi-turbo V8, which develops 449 hp and 516 lb-ft. The extra torque helps to get the SL 550 up to speed even quicker, and makes getting around town a lesson in restraint, as even mild application of the throttle delivers a shocking amount of power to the rear wheels. Only the most capable vehicles on the road could ever hope to give the SL 550 a run for its money when passing.

Despite the Roadster monicker, luxury convertibles are not the most fuel-efficient of vehicles. Equipped with the standard V6 engine, the SL 450 is able to get 20/28/22 mpg across the city/highway/combined cycles. This is mostly on par with rivals, although the Porsche 911 Carrera Cabriolet does slightly worse at 18/24/20 mpg, while the BMW 840i Convertible gets 22/29/24 mpg. The V8 that comes with the SL 550 trades efficiency for power, getting only 17/25/20 mpg. Fitted with a 19.8-gallon fuel tank, the SL 450 is able to cover around 435 miles before needing to pull into a gas station.