A couple of months ago, the Union of Concerned Scientists (UCS) first published its hybrid scorecard. That hybrid value reference source has now been updated with two newly available luxury models. UCS has used the Mercedes-Benz S400 hybrid and BMW X6 Activehybrid to illustrate what automakers have done right and wrong with hybrids.
The Mercedes replaces the V8 engine of the S550 with a smaller V6 engine when paired with its mild hybrid. Mercedes also doesn't tack on any extra mandatory equipment to inflate the already steep price. The result is a comparative value, with the S400 being the least expensive S-Class offered in the U.S. market.
By way of comparison, the X6 pairs the even more powerful 455 horsepower of the V8 engine found in conventional models with the two-mode hybrid system. Features like premium audio and other standard equipment add an extra $10,000 to the price tag. While the X6 gets a better fuel economy rating than the non-hybrid models (barely) the high-cost doesn't seem justified. UCS would prefer to see hybrid systems paired with smaller engines for even better efficiency and lower cost so that more people can afford them.