When it debuted in 2010, more than 50% of the components used to build the Chevy Volt came from foreign manufacturers. GM announced that it will begin building its second-generation electric drive unit at its facility in Warren, Michigan, in an effort to bring the domestic content of the Chevy Volt above 70%.

“We must provide the breakthrough technology that our customers want,” said GM CEO Mary Barra. “Our investments in the Chevy Volt and Michigan signify our commitment to lead the industry in technology and innovation.” The Warren plant will build the new Voltec Multi-Mode Electric Drive Unit, which currently makes between 148 and 201 horsepower, and to date GM claims Volt drivers have covered more than a billion miles, most of those on electricity alone.

GM has committed mightily to plug-in vehicles, claiming it has spent over $11.8 billion pursuing vehicle electrification including a battery facility in the Brownstone Township and the Detroit Hamtramck assembly plant where the Chevy Volt and Cadillac ELR are built. GM also has the Chevy Spark EV in its lineup, though that will probably be replaced by a slightly-large Chevy Sonic-based EV with a 200-mile range. A new 1.5 liter three-cylinder motor will power the 2016 Volt’s battery pack, and it’ll also be built in Michigan at the Flint Engine Operations plant.

With a refreshed ELR and a brand new Volt lining up to debut in the next few months, GM’s investment will go a long way towards making the Volt more American. That could make the Volt the most American plug-in car yet, though if the Tesla Gigafactory gets up and running on schedule, the Model S could end up displacing the Ford F-150 as the vehicle with the most American-manufactured content.