While Mercedes-Benz is a leader in clean diesel technology, the German luxury brand has been lagging behind its arch-rival BMW when it comes to the adoption of green technology such as stop/start in its lower-end models. This omission will soon change, as the A-Class and B-Class models, which are not sold in the U.S. market, will be granted the technology shortly. While consumers will likely appreciate the fuel savings most, the brand will be happy to report the reduction in carbon dioxide, which is regulated in most of the world.
The stop/start technology that will be used by Mercedes-Benz is a very basic system and is shared with the smart brand. Because the starter will be used much more often than normal, a larger starter motor and battery is required. BMW harnesses a portion of the energy usually lost when braking to recharge this more powerful battery. Mercedes' system does not allow this capability, though the automaker claims it is hard at work on the next-generation version of this technology which they say will incorporate regenerative braking.
[Source: Automotive News Europe - sub. req'd]