When a vehicle sits unused for more than two weeks, whether you are storing a seasonal car, working from home, or simply not driving much, it needs periodic attention to stay reliable. Fuel degrades, the battery drains, brake rotors develop surface rust, tires lose pressure, and rodents have been known to move into engine compartments. Here is what to do to keep things in good shape.
Fuel
Gasoline begins to lose volatility after about 30 days. If your vehicle will sit longer than that, add a fuel stabilizer to a full tank before you park it. A full tank also reduces air space inside the tank, which means less condensation, and less moisture working its way into the fuel system. Most fuel stabilizers extend shelf life to 12 to 24 months depending on the product.
Battery
Your vehicle draws a small amount of current even with the ignition off, from the clock, security system, and onboard computers. That draw is enough to drain a battery over several weeks of inactivity.
The simplest solution is to drive the vehicle for 15 to 20 minutes once a week. A genuine drive, not just idling in the driveway. The alternator needs the engine at higher RPM and some sustained run time to meaningfully recharge the battery.
If a weekly drive is not practical, a battery maintainer is the next best option. A maintainer (as opposed to a standard charger) monitors the battery and supplies a trickle of current only when needed, so it cannot overcharge. Solar-powered maintainers are a particularly convenient choice since they require no outlet.
Brakes
Surface rust on brake rotors is normal and not a concern for a vehicle that gets driven regularly. On a vehicle that sits for more than a week or two, that rust layer can become thicker and cause a pulsing or grinding sensation on the first few stops. It usually clears within a few miles of normal driving. If a vehicle has been sitting for several months and the pulsing does not go away after a few drives, have the rotors inspected.
Tires
Tires lose approximately 1 PSI per month and can lose pressure faster in cold weather. Check pressure before driving a vehicle that has been sitting, and bring it to the spec listed on the sticker inside the driver's door frame, not the maximum pressure printed on the tire sidewall.
If the vehicle has been parked in one spot for 30 or more days, move it slightly to take the weight off the contact patches. Extended sitting in one position can create flat spots, especially on tires that were already low on pressure or near the end of their life.
Rodent deterrent
Engine compartments are warm, sheltered, and full of wiring that rodents find attractive as nesting material. A single rodent can do hundreds of dollars of damage to wiring in a short time. Before storing or parking a vehicle for more than a few weeks, spray the engine bay and the area around the cabin air filter housing with a peppermint-based deterrent. Reapply every few weeks if the vehicle stays parked. When you do return to the vehicle, open the hood and check for any signs of nesting before starting it.
Before you drive again
After any extended period of sitting, check the tire pressure, look under the hood for obvious signs of rodent activity or fluid leaks, and note how the brakes feel on the first few stops. If the vehicle has been sitting for more than six months, consider having the oil changed and the battery load-tested before putting it back into regular use. Happy motoring.