We just received our first 2012 Mercedes-Benz CLS550 at the dealership. As I was looking it over, the first thing I noticed was the “blue efficiency” badge. That sounds an awful lot like the BlueTEC diesel engine. However, the window sticker gave non-diesel like numbers: 402 hp and 443 lb-ft of torque. Coupled with a 7-speed automatic the engine is good for 0-60 in 5.1 seconds and 26 mpg on the highway. High performance and good gas mileage are a rare combination. How did they accomplish that?
The efficiency is not the result of a high performance BlueTEC engine. Mercedes-Benz just decided to use the term “Blue Efficiency” to describe the incredibly efficient twin-turbo, direct-injection, 4.6L V8. According to Edmunds Inside Line, “some of the efficiency improvement is due to a stop/start engine function that won’t initially be available in stateside CLSs, as compliance of the system with U.S. emissions isn’t finalized.” Another review gives more detail.
In the CLS63 AMG, an Eco-mode allows for auto stop/start functions, which occur when the driver puts his foot on the brake, when stopped. As soon as the brake is released, and the accelerator is depressed, the engine re-fires and is ready to go. Multi-spark and multi-squirt technologies help to deliver more powerful and energy-saving efficiencies under the hood.
At the time of writing, little information has been made available to me about this new technology. But if ECO-mode ends up in the CLS550, I’m sure nobody will complain about a 402 hp sedan that gets better than 26 mpg.