Although it won’t arrive here until the fall of next year as a 2010 model, Mercedes-Benz has just released a detailed rundown on the finer points of its first hybrid luxury sedan that goes on sale in Europe next summer. Based on the existing S350, the S400 BlueHYBRID teams a modified version of the well-proven 3.5-liter gasoline V6 with a compact electric motor/generator unit positioned between the engine and a specially configured version of M-B’s sophisticated seven-speed 7G-TRONIC automatic transmission. The engine, which is fitted with variable valve-timing that uses the Atkinson cycle to further enhance its thermal efficiency and help lower emissions, makes 275 horsepower. The three-phase AC electric motor is powered by a new Lithium-ion (Li-ion) battery pack -- the first such dedicated Li-ion application in a series-production car -- and adds an extra 20 horsepower and 118 lb.-ft. of starting torque. Collectively, they develop a total maximum output of 295 horses and 284 lb.-ft. of twist. Mercedes claims this provides sufficient motivation to hustle the S400 BlueHYBRID from 0-60 mph in just over seven seconds while providing significantly better fuel economy than a baseline S350 and trimming comparative CO2 emission levels by 21-percent.
Like most of its contemporaries, the S400 BlueHYBRID is fitted with a start/stop function that shuts the engine off at full stops or when the car is rolling at speeds below 9 mph, as well as a regenerative braking system that recharges the battery pack on the fly. This ‘mild-hybrid” also offers a slick display in the center of the dash that monitors energy flow and battery status. What sets the this new S-Class apart from its hybrid brethren is that it doesn’t sacrifice any existing cabin or trunk space to gain the extra efficiency. Diligent effort on the part of M-B engineers enabled them to position the battery pack and all supplemental electronic control elements in the S400 BlueHYBRID’s engine bay.
The Li-ion battery pack also displays the kind of attention to detail you’d expect from M-B. Encased in a high-strength steel cage, it beds each individual cell in shock-absorbing gel to dampen road jolts and features a dedicated cooling system plus extensive fail-safe circuitry to prevent any major problems should the system ever malfunction or the vehicle be involved in a major frontal impact.
Mercedes has yet to release any solid pricing information on the S400 BlueHYBRID, but it’s expected to sticker somewhere on the far side of $100,000 when it finally does reach the U.S. late next year.