Currently, the EPA only allows a 10 percent maximum blend in "standard" gasoline (E10) at the pump. However the State of Minnesota and the Renewable Fuels Association released recently a feasibility study on upping that to a 20 percent blend in the state.
According to AllSAFE, more testing is needed to determine if E20 is really compatible for engines not originally designed for this fuel, as well as potential harm to catalysts, higher emissions and premature engine failure. AllSAFE also said that up to 240 million conventional vehicles and 100 million small engine products could be potentially affected by these blends. Only flexible fueled vehicles (FFVs) are designed, certified and warranted for use with ethanol blends greater than E10.