The Mercedes-Benz S400, the first production hybrid to use lithium-ion batteries, has been declared eligible for the IRS' Alternative Motor Vehicle Credit as a Qualified Hybrid Motor Vehicle. For the S400, this credit is worth up to $1,150. This puts the S400 near the bottom of the list, with vehicles like the 2009 Ford Escape Hybrid 2WD worth $3,000 and the Nissan Altima Hybrid getting $2,350.
In addition to the li-ion battery pack, the S400 offers auto-start-stop, electric assist, and regenerative braking capabilities. The EPA rates the S400 at 19 mpg in the city and 26 mpg on the highway
[Source: Green Car Congress]