The Mobil Station near me has E-85 for $1.99/gal. while regular is going for $2.59/gal Since I fill up my tank once every six months is E-85 a good thing to put in my tank?
From p. 719 of the Prime owner's manual- ●Use only gasoline containing up to 15% ethanol. DO NOT use any flex-fuel or gasoline that could contain more than 15% ethanol, including from any pump labeled E30, E50, E85 (which are only some examples of fuel containing more than 15% ethanol).
E85 has about 70% of the energy of E10, so expect MPG to be that much worse until the dash lights up with warnings.
If your car was rated to use E85 (your Prius is not!), then $1.99 is still more expensive per mile than the regular E10 fuel. Considering E85's lower MPG, a breakeven price would probably be around $1.90/gal. If higher than that, get the regular gas instead unless pollution issues suggest If you refill your Prime just twice a year, consider going the other way -- E0 instead of the regular E10. Numerous non-automotive uses try their best to avoid the ethanol in engines that are used only seasonally, then sit in storage the rest of the year. E0 is a bit overpriced for its energy content, but is reputed to be more stable in the tank and fuel lines.
Note that finding E0 may be difficult to impossible depending on where you are - there are web sites like Ethanol-free gas stations in the U.S. and Canada and Ethanol Free Gas Stations that list stations that sell E0 in each state. For example I'm in NJ, what are listed are all marinas and airports, not helpful to fill up a car :-(
Higher than E15 can be damaging to fuel system components over time. Flex fuel engines use more hardened materials, like stainless steel in their system. They also have higher flowing fuel injectors so enough E85 can be burned to get performance equal to using gasoline. Or simply out of the way or too expensive. The only places with it on my route are shops selling 100 octane racing fuel for $8+ a gallon by the jug.
I been on several GasBuddy betas and a contributing member since 2005. We begged the newest management group to add E0 as a station option and they refused to believe it was very prevalent across the country. The beta mgr is in Regina, SK, so how the hell would he know. Out of sight out of mind attitude. We're lucky to have more E0 than E10. It's too bad not everyone can find it. Sadly the Puregas web site is pretty out of date.
That is certainly inconvenient for those of us with regular non-plugin Prii and must fill up every month. Sometimes even twice. . But it is not unreasonable for Prime owners who fill up only once or twice a year.
