The 2010 Mercedes-Benz S400 Hybrid will combine an electric motor with a 3.5-liter V6. See pictures of the 2009 S-Class.

Consumer Guide's Impressions of the 2010 Mercedes-Benz S-Class Hybrid

Update 05.09.2011 

Click here for Consumer Guide's review of the 2010 Mercedes-Benz S-Class Hybrid.

Mercedes goes green in a big way with a first-time gasoline/electric version of its flagship sedan. The S400 Hybrid won't do much to save the planet, but guilt-stricken plutocrats should love it.

What We Know About the 2010 Mercedes-Benz S-Class Hybrid

Mercedes-Benz is preparing a squadron of efficiency-focused M-B models aimed largely at U.S. consumers obsessed with saving gas and saving the planet. All aim to deliver more miles per gallon and fewer nasty carbon emissions without sacrificing traditional Benz performance, refinement, or luxury, though they vary in their means to those ends.

• New Hybrid Car Prices & Reviews
  
• Reviews of All New Mercedes-Benz Vehicles
• All Mercedes-Benz S-Class Reviews

Kicking things off in a literal big way is a first-ever "mild-hybrid" version of Mercedes' S-Class premium large sedan. Dubbed S400 Hybrid, it's due to start production around mid-2009 and reach U.S. dealers as a 2010 model. Like others of its kind, the S400 Hybrid uses a battery-powered electric motor to assist its gasoline engine--here, a modified version of Mercedes' recently updated 3.5-liter V6. That means the S400 can't be driven on volts alone like the rival Lexus LS 600h, nor can it be plugged-in for recharging. So Mercedes seems to be going for simplicity, rather surprising for a brand that's never short on gadgets.

Even so, the 2010 Mercedes-Benz S400 Hybrid will be one of the first retail hybrid vehicles--maybe the first--to employ advanced lithium-ion (LI) batteries instead of the nickel-metal-hydride (NiMH) type favored by Toyota/Lexus, Honda, and other manufacturers. LI batteries cost more than NiMH cells, but can store more energy in a smaller, lighter package, making them better suited for automotive use. Mercedes teamed with French supplier Johnson Controls-Saft on the S400's batteries and claims 25 patents on this particular LI technology--which, by the way, it is not sharing with other companies, as far as we know.

Updated by Jennifer Geiger 05.09.2011 

For more inside information on hundreds of new cars of today and tomorrow, check out:

• 2009 Mercedes-Benz S-Class Review and Photos
• 2009 Consumer Guide Best Buy and Recommended Award Winners: Check out which cars won our Best Buy and Recommended awards for 2009.
• Future Cars: Step into the automotive showroom of tomorrow with reviews, analysis, pictures, prices, and preliminary specifications on scores of vehicles that will be appearing next year and beyond.