Question: what is the difference between unleaded and unleaded 15?
Answer: The new fuel is called E15 and contains 15 percent ethanol, compared to the 10 percent in regular unleaded. Though E15 is sold at the same pump consumers are used to, government warnings say it's not safe to use in every engine. ... On the pumps at KwikTrip, E15 is sold in the space that used to dispense 89 octane gas.