Adding gas/oil mixes to my auto's tank

I have a number of containers of gas/oil mixes used in garden tools, snowblowers, etc. that are leftovers from previous seasons. I don’t want to use them now in those items since the gas is old and may foul the carburetors on these small engines.



Can I add the gas/oil mixes to my auto’s tank without causing a problem? If not, how do I dispose of the old gas?

Here are several answers often given to that question:

  1. Are you nuts? You have gas that’s old enough that you won’t add it to your - comparatively cheap - small engine, but you’re thinking of throwing it into your very expensive car instead? Don’t do it.

  2. Don’t put a lot in all at once, but if you toss a quart or two into a full tank of fresh, clean gas once in a while it probably won’t hurt anything.

  3. How long are we talking about for the “previous seasons?” It might be just fine to use in your small engines, but don’t put it in your car (see #1). Add some fuel stabilizer and keep using it as normal. (I use this option, but I start with the stabilizer).

  4. Don’t put it in anything! Call your local (county/city) waste authority and ask them about their hazardous waste disposal program and bring it there. (Mine is actually quite easy - free and quick drop off for county residents).

  5. I’ve never actually heard this one, but Sea Foam (I think it is - maybe it is a Lucas Oil product) claims to “refresh” old gasoline. Add some and use it in your small engines.

  6. But you won’t hear this from anyone else b/c it is a little family secret invented by a couple of uncles of mine when they were kids: build a Martian trap! Dig one hole in the ground. Fill with gasoline. Apply match! Talk about some fun weekend fireworks. Seriously - they tried to do that, but luckily got caught right before striking the match. Don’t try that one.

There might be more…

It depends on how old it is…How many “seasons”…2 years would be the upper limit to use “stale” gas. A little 2-stroke oil won’t hurt a thing… Just think of it as “top oil”…

My first thought is to worry about the affect of the 2T oil on oxygen sensors and catalysts.

I don’t think that it would cause any harm at all.

I would trickle it in a quart per tank full until it is gone. It is probably more environmentally responsible to get energy from it than to take it to Haz Waste disposal (depending on what state you are in and what they do with it).

In extremely small quantities it won’t bother. Eg 1/2 to 1/4 gallon added to 12 gallons is pretty dilute. My serious concern would be to make sure fuel is clean, my 2 stroke can have “floaty’s” in them. I simply run it in my lawn tractor.

Most two cycle oil has some fuel stabilizer in it. Do you know it is too stale to use in your garden tools? It might be safer to use it in your snowblower than in your car.

I agree with #1. Why risk components that would cost hundreds of dollars to replace?

#6 is good if you live in the country. And have a ready supply of marshmallows. And a field. And a tractor to clear a good sized area of grasses and brush.