Mixing Ethanol & Non Ethanol Gas-Good or Bad?
Below is the comments from a Merc Technicician from another Board "Bass Boat Central" concerning mixing fuels. I live on the Eastern Shore of VA and more places and marinas are starting to sell non ethanol gas. I thought it might be a good idea to run a tank of Non Ethanol fuel through my boat. I probaly won't now. I just put a 2009 Merc 225 Pro XS on my boat and was checking this site for info about these motors. Anybody looking for good info on motors and a host of other info, this is a good board. This site is geared toward Bass Boats & fishing but the motor information is great.
A couple other factors to consider:
1. FRESHNESS OF FUEL. You're better off with fresh, 4% ethanol content fuel (compared to 60 day old non-ethanol fuel). This is one reason to consider "higher traffic stations".
2. Incompatibility: Switching back and forth between E10 and "Non-Ethanol" fuels can lead to fuel system degredation, and "phase separation" of your fuel. Either will cause performance issues.... or may leave you "dead in the water".
My suggestion: Pick a fuel that BOTH YOU, AND YOUR BOAT are happy with.... and stick with it "as exclusively as possible".
(Certified Mercury Technician)- Mercury Outboards, Mercury Racing and Mercruiser Sterndrives, Greenville, SC
Not an expert by far- now working on 34th year as a "Marine Apprentice" (still learn something new every day). BBC Sponsor
I don't see how mixing, itself, will cause any issues. The issue is caused by E10 and its phase separation. So obviously if you don't use ethanol you don't have the problem, but since most gas now is E10, the best program is to treat all gas as if it was E10. BTW all gasoline has additives including ethanol or similar solvents, and the actual content can swing wildly in fuel marked E10.
But you are lucky up there on ESVA to have access to non-ethanol fuel.
Yea, I don't know all the answers when it comes to chemicals. I don't know why mixing would lead to phase separation any quicker? It does seem to m,ake sense to find something that runs in your boat a stick with it, if one tends to refeul at the same place often.
Maybe we have a chemist on here who can chime in.
Wont matter at all or do any harm as long as the fuel doesnt have any water in it you will see no difference.
I have mixed both and have not seen any performance issues with my Yamaha 200 two stroke.
The lower the Ethanol concentration, the higher the probability of phase separation. Phase separation will result in extremely low octance fuel to your engine along with the risk that the water/ethanol mix might get into your engine. As long as you don't run your tank down below a 1/8 before refill, the concentration shouldn't get low enough to be an issue. Safest thing to do, as recommended, don't make it a habit of switching.
E10 will hold way more water in suspension than MTBE fuel. lets say you have 50 gal of E10 and its holding 1\2 gal of water in suspension. Then you add 50 gal of mtbe fuel which will reduce the ability of the E10 to hold the water. The water then "Drops Out'' of suspension and falls to the bottom of the tank. I would not mix it. The only water I have seen in my fuel system was when I changed over. When changing to E10 run your tanks as low as possible and then watch yer water separator. The water is only one of the issues with E10.
Originally Posted by home cookin'