Year-old gas in tank

My mother has given me a 2003 Honda Accord that has been sitting in the garage for more than a year without being started. Should I have the gas drained out of the tank? Or just charge the battery, see if it starts up, and hope for the best?

Start it and see if she’ll run. Maybe you’ll get lucky?

Tester

Yes, you could get lucky. I would also check the brakes to see if the master/wheel cylinders aren’t bypassing due to disuse for a year. It may run but you may not be able to STOP!

Pressurize the fuel system before you start the car. Turn the ignition key to on, but not start, for 2 seconds about 5 times. This will re-pressurize the lines and make the first start easier.

1 year old gas should fire up fine, but you may want to fill up with fresh gas and a can of Seafoam at your earliest opportunity.

It’ll probably run a bit rough as gas starts to go bad after 6 months, but it’s not so old that it won’t run at all. Charge the battery all the way and then get driving and use up some of that bad gas.

The gas was stored indoors in a car’s (for all practical puroses) sealed gas tank. I’ll bet it’s just fine. Gas goes bad because the lighter and easier-to-start-engines-with faction evaporates off and leaves behind the heavier, more-difficult-to-start-engines-with stuff. The lighter stuff also has a higher octane rating than the heavier stuff so once you do start an engine with old gas, you may experience a lot of detonation.
The molecules of gasoline do not self-destruct with age, the gas you buy is probably millions of years old when it’s pumped out of the oil well.

Gas goes bad because the lighter and easier-to-start-engines-with faction evaporates off and leaves behind the heavier, more-difficult-to-start-engines-with stuff. The lighter stuff also has a higher octane rating than the heavier stuff so once you do start an engine with old gas, you may experience a lot of detonation.

Yes and no. Yes the lighter fractions can evaporate off faster, but since modern tanks are sealed, they have no place to go, so that is a non-issue. I don’t remember my college organic chemistry well enough, but I don’t believe there is a direct relationship between molecular weight and the octane rating. In fact various forms of octane will have different octane ratings.

The real trouble with old fuel is that over time the various hydrocarbons will polymerize into longer - larger chains. The stabilizers sold reduce the rate of this change. It does not involve evaporation.

Hmm… Well, I think now that I will just jump start the car and see if it starts (and stops.)