U.S. researchers said the technology used to heat and cool car seats has the potential to improve gas mileage.

Northwestern University researchers said thermoelectrics can convert waste heat into electricity to help power a car. The team created a thermoelectric metal that is more efficient than existing materials, the university said Wednesday in a release.

The findings are published online in the journal Angewandte Chemie.

A thermoelectric device could be attached to a car's tailpipe to generate electricity that would be returned to the car's engine for additional torque, the report said. Senior author Mercouri G. Kanatzidis, a chemistry professor at Northwestern, said automakers are working on thermoelectrics in an effort to improve gas mileage by 5 percent to 10 percent.