In conjunction with it’s 70th anniversary making oil burners, Mercedes Benz had something very interesting to show us at the 2005 Geneva Motor Show.

The Mercedes Benz SLK320 CDI Tri-Turbo Vision

Mercedes Benz’s history making diesel engines goes all the way back to 1935 when they rolled out the 260D, a diesel powered mid sized sedan making 45 horsepower with it’s 2.5 litre inline-four diesel engine. Diesels were only invented 38 years before that, by Rudolph Diesel.

Fast-forward 70 years later, Mercedes Benz showcased their concept SLK320 CDI Tri-Turbo Vision powered by a new 3.0 litre common-rail direct injection tri-turbo diesel V6 engine. The oil burner comes with 4 valves per cylinder. What’s special about this concept engine is the usage of 3 turbochargers to minimize turbo lag and maximize performance.

How does it work?

The engine is driven by 2 small turbochargers and 1 large turbocharger. Each small turbocharger drives 1 bank of cylinders at both sides of the engine, and these are in turn are connected to 1 single large turbocharger positioned in the middle of the 2 banks of cylinders in the V6 engine. At low RPMs, all three turbochargers are at work, with most of the boost provided by the small turbochargers while the big turbocharger spins up. Later, a bypass is activated and air flows through the big turbocharger alone supplying a huge boost and massive amounts of torque.

What does this give us? 286 horsepower and 628Nm of torque. The car goes from 0-100km/h in 5.3 seconds. How does this figure stand up to the SLK350 powered by a petrol engine? The SLK350 does it in 5.1 seconds. Only 0.2 seconds difference. Very impressive.

The engine also makes 14 extra horsepower and 69Nm more torque than the BMW 3-litre inline-6 turbodiesel which won the diesel engine of the year award for 2005. However the BMW oil burner is a production engine but this Mercedes Benz is still a concept. Mercedes officials say it is still too expensive to mass-produce.