It’s been about three-and-a-half weeks now since I filled up a couple 5-gallon containers in anticipation of power outages during a winter storm. Since I’m a dumb dumb, I did not add stabilizer at the time, but I do have some Seafoam stabilizer on hand.
I understand fuel degrades over time and running degraded fuel can damage engine parts. Should I pour the fuel into my vehicle or will that gum up my car’s engine? Is it still worth adding stabilizer today so that I can continue to store it in my garage for a rainy day? The only other responsible alternative I can think of is taking it to a hazardous disposal site in my county. It’s octane rating 87, I believe it also has ethanol, in case that makes any difference.


If you are concerned about it, you can mix 5 gallons at a time in your car with the remainder being fresh gas. I.e. if you have a 15 gallon tank, use 10 gallons of new gas with 5 of old.
3 weeks isn’t all that long though, its probably fine as long as you didn’t leave the cap off.
What kind of car is it potentially going in?
Thanks for weighing in. It would be going into a Mazda 3 or a Honda CRV.
If they are non turbo, it should be fine. If they are turbo cars, run premium for the new fuel and use a minimum 3 to 1 ratio of new to old fuel just to be safe.
Really, 3 weeks is fine but I don’t want to lead you astray and cause problems here lol. I’d run it though.