US: EPA economy rules could hinge on advanced transmissions image

Just like the European Union across the Atlantic, the US is increasingly pressuring automakers to improve fuel economy and thus lower the harmful greenhouse emissions.

With a report coming from the Environmental Protection Agency stating that 2013 model year cars and light trucks have a 0.5 mpg better average, concerns have been raised about the automakers’ ability to meet the industry wide rules to be implemented in 2025. That’s because the advancement slowed from 1.2 mpg for the 2012 model year vehicles and is expected to creep down to 0.1 mpg this year.

But the carmakers have numerous ways to reach the record US fuel economy level required by the federal regulators: advanced transmissions. With US buyers traditionally favoring automatic transmissions to the more technical manual gearboxes, carmakers are increasingly relying on automatics to also yield fuel economy improvements.

While Porsche has been the only one so far to add another gear to the manual transmission (and has moved it to being the optional choice), carmakers have no discomfort in using seven, eight and even nine gears for their automatics. Usually – although surprisingly not always – the higher the gear count, the higher goes the mileage too.

And, according to Aaron Hula from the EPA vehicle test lab in Ann Arbor, Michigan, the latest study from the agency has found that the benefits of manual and automatic transmissions are roughly equal today.