General Motors is hoping to gain an advantage over its competitors’ hybrid car offerings with the Chevy Volt, an extended-range electric vehicle. The Volt promises to be so fuel efficient, GM says, that it will let some drivers almost completely stop visiting gas stations.

Since cars started puttering around on America’s streets early in the 20th century, there have been several attempts to replace gasoline-powered internal combustion engines with all-electric motors and batteries. These attempts failed, in no small part because it was difficult to recharge the vehicles when they ventured outside their local range. In recent years the solution has been hybrid vehicles that recharge their batteries on board, thanks to a generator connected to a gasoline-powered internal combustion engine. Although this is more fuel efficient than a pure internal combustion vehicle, all the energy these hybrids use to move the vehicle ultimately comes from gasoline.

The Chevy Volt’s lithium-ion battery pack, in addition to being rechargeable on board by an internal combustion engine, can also be charged from an external power source—specifically, regular household current. This means that drivers can plug in their vehicles to recharge overnight and get up to 40 miles of driving the next day from about 80 cents’ worth of electricity. When the vehicle goes beyond the 40-mile mark, the internal combustion engine kicks in, powering the car and partially recharging the batteries, giving the car a total range of about 400 miles.