Naturally aspirated engines seem destined for the endangered species’ list as forced induction makes its way into nearly every mainstream category. The latest example is the new SL400 roadster Mercedes announced today. It’s a direct replacement for the SL350 roadster with the only real change centered around the new 3.0-liter, twin-turbocharged V-6.
The new biturbo V-6 might be down on displacement from its 3.5-liter predecessor, but it makes up for it with power — 26 extra horses and 81 extra pound-feet. Mercedes says 0 to 62 mph time will drop 0.7 seconds, doing the deed in 5.2 seconds on its way to its 155-mph governed top speed. While Mercedes does have a nine-speed transmission available for use, the German automaker decided the current seven-speed unit would suffice for the SL400.
The biturbo V-6 was first seen last year in the E400 sedan, though it made less power. Like that engine, the SL400’s mill features some pretty snazzy tech to create tire-turning torque while keeping the EPA (and customers’ wallets) happy. Its direct-injection fuel system features Piezo injectors that squirt fuel up to five times per power stroke for an even burn. The pressure at which they operate is varied based on engine mapping and certain conditions. Lighting the fuel is an ignition system that creates multiple sparks over during the same power stroke of each piston. Just like the fuel, the individual spark events are variable in their timing — all in an effort for the cleanest, most power-producing burn possible.
Mercedes says the SL400 will get 32 mpg while producing minimal tailpipe emissions.
Click past the jump to read more about Mercedes-Benz SL 400.