Your gas car works fine. Consider an EV anyway.

A new study published in the journal Science finds that switching from a gas car to an electric vehicle almost always cuts lifetime emissions, even when you factor in the emissions created by manufacturing the EV and its battery. The researcher, Elliot Campbell of UC Santa Cruz, set up the study to favor gas cars as much as possible, and the EV still came out ahead. Even trading in a car that's only two years old for an EV can cut emissions roughly in half over its lifetime.

Other research backs this up. Separate analysis found that EVs typically pay back their manufacturing emissions after about 18,000 miles of driving, which the average driver covers in about a year and a half. How big the benefit is depends on where you live and how your local electricity is generated. In upstate New York, where hydropower is common, driving an EV is like driving a gas car that gets 219 miles per gallon. Even in the Rockies, where coal and gas dominate the grid, an EV still beats any gas car getting less than 68 mpg.

The main exceptions are plug-in hybrids with larger batteries, and cars that rarely get driven, like a second vehicle used only occasionally. For most typical driving, though, researchers say there's no environmental reason to keep a gas car running longer just to avoid the emissions of building a new one. The study didn't look at purchase price or other costs, only emissions.