Unleaded 88 coming your way? in General E85 Discussions Posted August 30, 2017 · Report reply I like under E50 for vehicles. E30 would quickly become my favorite. All vehicles that I've experience do well under E50. My wife's Focus will drop 2 mpg on E30 E40 fuel. Given that the E85 fuel is -60 cent continuous spread I'm making out good. Funny, that the Costco pumps may be as much as -10 cents per gallon and you have to get in line with six deep to fuel up. If ever the public would realize the true benefit of ethanol, you know given that the fuel really is a superior fuel, what would be the results? And yes the regulations to improve production and use of ethanol should have merely allowed ethanol to mix straight up with gasoline and advertise as mid and high octane fuel.