Q: I have a car that has not been driven in more than a year. Is there anything I should do before driving it? How long can gasoline last in the fuel tank and still be good?
A: A year is a long time for a vehicle to sit unused, especially if no steps were taken before it was parked to prepare for its long hiatus. Before starting the vehicle, the battery will probably need to be charged—or replaced. While you’re under the hood, check all the fluids, the condition of the drive belt (or belts) and hoses. Also, look for rodent infestation and damage, paying particular attention to the air filter housing and wiring harnesses. Under the car, examine the fuel and brake lines, exhaust system and tires.
If all is well, start the car. Some people will first crank the engine a few times with the ignition or fuel pump disabled to get the oil circulating and then restore ignition or fuel pump operation so that the engine can start. After the engine has run smoothly for a minute or two, drive slowly and carefully for about five miles, and then perform all the under-hood checks again.
Gasoline will generally remain usable for three to six months, though I’ve seen cars start and run using gasoline that has languished in the tank for two years. Cars that will be unused for up to three months should be stored with a full tank of fuel to reduce the likelihood of condensation forming. Adding fuel stabilizer may extend the fuel-storage period to a year. For storage that will last more than a year, drain the fuel system.