EPA Awards Mercedes MPG Credits For Start-Stop Tech

S 350 BLUETEC  ( W 221 )  2010

The EPA has awarded Mercedes-Benz extra fuel economy credits for bringing start-stop and other efficient technologies to its entire fleet of luxury cars, reports Automotive News, even though the benefits don’t show up on official MPG ratings.

The EPA’s fuel economy ratings underwent a major revamp a few years ago to better represent real-world driving, but there have been calls to revise them once again to take into consideration advances in technology. Stop-start technology, which shuts down the engine when the car comes to a complete stop in order to conserve fuel while idling, is one of those new technologies that testing procedures haven’t caught up with. Even though the technology is relatively cheap to introduce and can yield as much as a 7% increase in fuel economy, automakers have less incentive to employ it in cars because it doesn’t show up on window stickers or in regulatory considerations.

Because Mercedes has regularly failed to meet EPA fuel economy standards, the German automaker has shelled out nearly $350 million in annual fines between 1985 and 2011. Mercedes has since requested “extra credit” for implementation of energy-saving features like LED lighting, ventilated seats, and window glazing that better retains the car’s climate, asking the EPA to credit it between 9.1 to 19 grams of CO2 credits per mile. While the EPA granted most of the credits for energy-saving technology, it only allowed Mercedes to claim 3.4 to 4.3 grams per mile, putting the onus on the automaker to prove start-stop saves as much fuel as they say.

That said, if Mercedes can return with better proof, the EPA may very well change its stance on start-stop technology. Some automakers are implementing the technology regardless, and it’s one of those technologies that will likely become as commonplace as fuel injection and disc brakes in another decade or two. The systems are estimated to only add a few hundred dollars to the cost of a car, but the fuel savings in heavier vehicles especially can pay off the premium in just a couple of years time.

Will your next car have stop-start? Well mine won’t, ’cause I’m going electric!

Christopher DeMorro

A writer and gearhead who loves all things automotive, from hybrids to HEMIs, can be found wrenching or writing- or else, he's running, because he's one of those crazy people who gets enjoyment from running insane distances.