Mercedes-Benz hasn't publicly announced an official on-sale date yet for its first hybrid models beyond the first half of 2009. However, BusinessWeek is reporting that the S400 BlueHybrid will go on sale in Europe in June 2009. The big gas-electric luxury sedan is due to arrive on U.S. roads one year from now. The S400 will use a lithium-ion battery pack and will likely be the first from a major automaker to do so. With a current U.S. base price of $86,700 for an S550, it's not quite clear where the hybrid will fit in the U.S. lineup. The S400 will pair the 3.5L V6 that is not available in the U.S. S-Class with the Daimler/BMW mild hybrid system. BusinessWeek reports the system will command a premium of less than €10,000 (I should hope so, since that's almost what Lexus charges for the full hybrid system on the LS600h). On the plus side, the Mercedes should get significantly better fuel economy than the Lexus. Mercedes is claiming 29.8 mpg (U.S.) for the hybrid although it remains to be seen how it will fare on the EPA cycle.