Just days after announcing an upcoming line of clean diesel products dubbed “EcoDiesel,” Chrysler has filed paperwork with the U.S. Patent and Trademark Office to claim the “HFE High Fuel Efficiency” name as its own.

As Car and Driver reports, the automaker had previously used the “Aero” descriptor on products deemed to be the most fuel-efficient, such as the Dodge Dart Aero, which will deliver estimated fuel economy of “at least” 41 mpg highway when equipped with a six-speed manual transmission.

However, the “Aero” name can also be linked to semi-defunct automaker Saab, which previously used the descriptor for its range-topping vehicles. It’s not clear if Saab had  trademarked the name, and if so who currently owns the rights to it.

While that may be the reason for Chrysler’s filing, even Car and Driver admits that this is just a theory. It’s equally likely that Chrysler wants a unique identifier to highlight its most frugal vehicles, and “Aero” communicates more than just fuel efficiency.

This makes sense to us, since it seems to follow conventional wisdom adopted by Chevrolet (which uses Eco for its fuel-sipping Malibu and Cruze models) and Honda (which has traditionally used HF badging for it’s high-mpg cars).

As for what Chrysler’s HFE vehicles may look like, don’t expect radical changes from current models. Instead of hybrid powertrains, expect HFE models to come with small-displacement gasoline engines, and to be equipped with low rolling resistance tires and enhanced aerodynamics to further lower wind resistance.