Fuel Storage Procedure

QuestionI just came across an old question (Ask the Experts, January 2011) about mixing E10 and pure gas. You said not to let the mix sit more than a couple of weeks. Does this advice still stand? Four of us old-timers (65 plus) had fun running most of the E10 out of my 2007 Sea Ray Sundeck. About seven gallons remained when the boat launch closed. I then put more than 42 gallons of pure gas in to fill it for indoor winter storage. I didn’t have the stabilizer with me, but I plan to put some in and tow it around to mix it before I run it for the oil drain. Am I safe?

Dale Sain, Bonney Lake, Wash.

AnswerThanks for keeping in touch and being a loyal reader! Your referral to “old timers” hurt, and bad: Since I became a septuagenarian, you’re still a kid — respect your elders!

Procedures have changed with time. The preferred way of doing things now is to run the fuel tank as low as you can with stabilized fuel (regardless if E10, or non-ethanol), winterize the engine and start off the next year with fresh fuel. If you have 42 gallons of non-ethanol mixed with seven gallons of 10 percent ethanol, and you’re using a good stabilizer that will enter the engine’s fuel system as you warm the engine to winterize it, I see no problems. If you segregate what you have in the tank, and stabilize it, while ignoring the engine’s requirements/expectations by feeding it unstabilized fuel, then I see trouble ahead.

One thought on “Fuel Storage Procedure

  1. You are 100% wrong on your statement that you should store your fuel tanks low.

    With e10 just 0.3% water, 1 tablespoon per gallon, causes phase seperation taking the alcahol out of solution turning it into a gelled mess and droping the octane 2 to 4 points. The lower the tank level the more condesation is created and the less fuel available to absob it. No additive reverses phase separation. Fuel tanks must be stored 7/8 full to avoid this. Where did you get the incorrect information about storing your tanks near empty? You need to correct the misinformation.


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