WASHINGTON (WTVO) — The U.S. Energy Department has proposed reducing electric vehicles’ mileage ratings to meet government fuel economy requirements.

The department wants to significantly revise how it calculates the gasoline-equivalent fuel economy rating for electric and plug-in electric hybrids.

It said that encouraging adoption of electric vehicles can reduce gas consumption, but giving too much credit for that adoption can lead to increased net petroleum use. This is because it allows lower fuel economy for conventional vehicles.

Cutting EV milage ratings could force automakers to sell more low-emissions cars or improve conventional models.