Frankly, standardization is often the only option given the limits of a universal technology standard. 1  1. Standardization lag: It takes time to understand a problem domain well enough to make a proper standard.
A flexible-fuel vehicle (FFV) or dual-fuel vehicle (colloquially called a flex-fuel vehicle) is an alternative fuel vehicle with an internal combustion engine designed to run on more than one fuel, usually gasoline blended with either ethanol or methanol fuel, and both fuels are stored in the same common tank.
Flexible-fuel vehicles in the United States. Flexible-fuel vehicles in the United States are the second largest flex-fuel fleet in the world after Brazil, and there were about 17.4 million flex-fuel cars and light trucks in operation by the end of 2014.