Definition: A flexible-fuel vehicle (FFV) is an automobile that can alternate between two or more sources of fuel such as gasoline or ethanol mixtures. Many flexible-fuel vehicles can accept a mixture up to 85 percent ethanol (E85) or up to 85 percent methanol (M85)and 15 percent gasoline. The fuel mixture is automatically detected by one or more sensors, and once detected, the ECU tunes the timing of spark plugs and fuel injectors so that the fuel will burn cleanly in the vehicle's internal combustion engine. These sensors are located in the exhaust manifold, before the catalytic converter. E85 and M85 are more corrosive, special fuel system materials are also required. Some manufacturers also suggest that special motor oils be used, especially for vehicles that utilize methanol fuel.
Also Known As: Dual Fueled Vheicle, FlexFuel Vehicle, FFV