General Motors said Wednesday it will launch a car next year with the ability to operate on both gasoline and compressed natural gas, taking advantage of abundant US gas supplies. GM chairman and chief executive Dan Akerson unveiled the new dual-fuel Chevrolet Impala at an energy summit in Washington marking the 40th anniversary of the OPEC oil embargo. The 2015 model year sedan will be offered to customers beginning in mid-2014. GM says it will be the only manufacturer-produced full-size bi-fuel sedan in North America. Akerson said the bi-fuel Impala would use \"affordable technology\" to reduce oil consumption and save consumers money at the pump The powertrain will switch \"seamlessly\" from compressed natural gas to gasoline at the touch of a dashboard button. The car will have a range of up to 500 miles (800 kilometers), and its ability to use both fuels will reduce user fears over replenishing the tank in a natural gas-only vehicle. GM, the largest US automaker, pointed to natural gas as a cleaner-burning transportation fuel compared with petroleum products and its significantly lower cost than gasoline at current prices. The conference -- OPEC Oil Embargo   40: A National Summit on Energy Security -- was focused on the 1973 OPEC oil embargo that crippled the economy and assessing the country\'s dependence on oil imports. \"We know that US energy security won\'t come from a one-off moonshot,\" Akerson said. \"It will flow from our systematic investment in technology and innovation,\" including a drive to get more from existing energy sources and renewables and a commitment to conservation. \"And it will be assured by fully and safely exploiting our shale gas reserves,\" he said.