2007 LA Auto Show: Mercedes-Benz S400 Bluetec Hybrid Concept Preview

Mercedes-Benz has taken its Bluetec V-6 diesel engine and mated it with a hybrid system. Result? Claimed fuel economy of 40 mpg on the highway (European test cycle) and acceleration to 60 mph in a shade over seven seconds, which is none too shabby. Also not surprising given the 265 horsepower and 465 lb.-ft. of torque produced by the dual power plant. Mercedes says the car will arrive in the States after 2010. Beyond those tidbits, very few details were parceled out.

The marriage of a clean diesel engine to an electric motor is almost too obvious, sort of like peanut butter and chocolate. Diesels have better fuel economy than comparable gasoline engines, so less carbon dioxide is produced. Mercedes uses urea injection, the blue in Bluetec, to control nitrous oxide and particulate emissions. The substance is stored in a tank that’s refilled during regular maintenance. The automaker’s E320 sedan won the 2007 World Green Car Award and it does meet the 50-state standard, so Mercedes lays claim to making the cleanest diesel.

Mercedes-Benz takes its turbocharged V-6 diesel and mates it to an electric motor. The company rates the S400 at 265 horsepower and 465 lb.-ft. of torque, the latter being just the kind of grunt needed to get a large luxury sedan that could weigh 5,000 pounds up to speed. By comparison, the E320’s 3.0-liter turbo diesel six has 210 ponies and 388 lb.-ft. of twist.

The automaker calls it 40 mpg economy with V-8 performance, and that’s not inaccurate given how slowly it sips diesel and how quickly it reaches speed. While scant on details on the S400, Mercedes used the press release to talk quite a bit about the E320 and its availability in California, which is limited and lease only.

Diesel hybrids might not be the automotive equivalent of a Reese’s Peanut Butter Cup – a fuel cell hybrid comes closer with its zero emissions – but it’s a smart combination for larger, heavier vehicles. Price is probably going to be a barrier to many buyers because diesels are more expensive than gasoline engines, and hybrid systems add even more dollars to the cost. Balancing out the initial investment are the longevity and efficiency of diesel engines and the added economy of a hybrid.

By Bob Beamesderfer Photo Credit: Staff