When to use gas preserver?

2004 Honda Accord. We’re storing this car, and using it every few months. The issue is how to treat the gasoline to preserve it (e.g. StaBil). I understand that treatment is important it the gasoline is left for many months. But every three months, we use maybe a third of a tank, and top it off with fresh gas. Does that fresh gas top off do the preservation trick, or should I be doing a full treatment on a topped off tank every three months? In principle, I could end up with a tank that has been over-treated.

I’d use it just to be safe, it’s cheap and I can’t see you over treating it if you follow the label instructions.


Agree with @texases If you add 5 gallons, include the proper amount of StaBil for 5 gallons. You will never overtreat if you do that.

It is taking 9 months to fully use a tank of gas and gas can start to go bad after 3-6 months. You are a bit on the borderline for using it or not. Can’t hurt!

Be sure you are changing your oil as recommended by Honda, too. XXXX miles OR XX months, whichever come first. If you don’t have that info, use full synthetic oil and change it and the filter once a year.

1 Like

I would go one step further, use non-ethanol gas in addition to the stabil.
You will not over treat as long as you use no more than the specified amount of stabil. Fill the tank, note the number of gallons of gas added, then only add the amount of stabil for that amount of gas.

1 Like

Well, OK. But my point was that it after 3 months, I treat a full tank with 5 oz of StaBil, and three months later I’ve used a third of that tank, then when I top it off and treat it again with 5 oz of StaBil, I’ve double-treated 2/3 of the tank. That is NOT consistent with label instructions. Are you saying that it is OK to double or triple treat with StaBil?

Do the math. If the entire tank treatment is 5oz, and you add 1/3 a tank, use 1 2/3 rds of an ounce (1/3 of 5 oz) for the fuel you add. No overtreatment.


Yes, that makes some sense. Just add treat the new gas I’ve added. Will do. Thanks.

Just start with a full dose. Here’s the dose by treated volume.

1 Like

Using Mr. Google seems to confirm that you really have to use a lot of the product Stabil to cause problems . Something like a 1 to 1 ratio .

Here’s what they say:

Will over-dosage cause any harm?

No, over-dosage is perfectly OK. However, we do not recommend adding more than 4 times the recommended amount. If more than 4 times has been added we recommend diluting the fuel.

For cars that are only periodically driven and going into storage the solution is:

  1. Fill your gas tank .
  2. Use a Top Tier gas.
  3. If at all possible, before going into storage, run down your existing fuel as low as possible, top up with fresh gas and Stabile, run it long enough chase any moisture out of your crankcase and cat and get the Stable/gasoline mixture all the way through your fuel system.
  4. And when you’re running it, periodic use of Chevron Techron to help reduce varnish build up.

I’ve got a 2004 and a 2005 that see similar use and “knock on wood”, the only fuel system exhaust problem was has been an injector failure.


Here’s another data point. I haven’t driven my prior daily-driver Corolla in nearly 3 years – Covid-related issue, truck is now daily-driver instead. Haven’t used any gasoline treatment in Corolla at all. I do idle the engine for 20-30 minutes once a week though, so have to pour in some more gasoline once in a while. I’d guess I’ve poured in about 5 gallons over the course of 3 years. That method has worked out ok for me anyway.

Full disclosure: I did have a problem with smoky exhaust at one point. Decided it was caused by water in the exhaust system b/c I was idling engine with car facing down. Turned car around so it was facing up, exhaust down so water could run out of exhaust pipes, problem resolved.

One can get away doing less, but why take the risk?

Fully concur, why take on a risk you don’t otherwise have to take?

Yep, that worked for me for about ten years until the fuel pump would not turn on any more. Then it was happy hunting ground time. I always used the non-oxy fuel also, same as for the lawn mower and snow blower.

Sure doing nothing probably might work but why take the risk?

A full tank of gas (you’re going to use it anyway) and $10 for a bottle of Stabile when you put it away and a $10 for a bottle of Techron when you start it vs. the cost of a rusted fuel line or the cost of a clogged fuel injector or stuck fuel pump? Or even worse, a rusted out Cat/Exhaust that’s been left with moisture in it’s system?

Modern cars (anyhing after 2000) are amazing examples of engineering but in extreme conditions still require a minimal amount of preventable maintenance to assure proper performance and longevity.
So would you rather pay $20 each interval to avoid problems or $300 tow charges and repair cost

I think putting 5oz Stabil in once or twice a year would be close enough to prevent trouble.

I used up the last of my Briggs gas treatment which was 1oz per 5 gallons. My stabil jug says 2 oz per 5 gal. Walbro came out with their fuel treatment so I ordered that never quite trusting stabil. Walbro is 1 oz per 5 gallons. I’m just going to use Walbro. Designed for small engines though not cars.

Hmm, Walbro— “pleasant evergreen scent”!
One bottle would last me about five years between the lawnmower and boat, do open bottles of fuel stabilizers go bad?
Above question is in jest.
Unused gas for boat, 1:50 oil mix, goes into the lawn mower.