For storage beyond roughly two to three months, fuel stabilizer is essential (untreated gasoline can start degrading within 30-60 days), the battery should be disconnected or kept on a smart tender, and tires need either slightly elevated pressure or the car raised on jack stands to prevent permanent flat spots. Change the oil before storage rather than after, since used oil contains contaminants that can slowly damage internals while sitting, and seal exhaust and air intake openings against rodents with fine mesh or steel wool.
At a glance
| Task | Why it matters for long storage |
|---|---|
| Fuel stabilizer + full tank | Prevents fuel degradation and tank condensation |
| Fresh oil change before storage | Removes contaminants that damage internals if left sitting |
| Battery disconnect or tender | Prevents deep discharge over months |
| Tire pressure +/- or jack stands | Prevents permanent flat-spotting |
| Rodent-proofing intake/exhaust | Prevents nesting and chewed wiring |
Fuel: stabilize it or drain it
Gasoline begins to break down chemically within roughly 30-60 days, forming gum and varnish deposits that can clog fuel injectors and lines. For storage longer than about a month, add a fuel stabilizer to a full tank (a full tank reduces air space and condensation) and run the engine for 5-10 minutes afterward so the treated fuel circulates through the fuel system, not just the tank.
Oil and fluids
Change the oil and filter before storage rather than waiting until you take the car out again — used oil contains acidic combustion byproducts and moisture that can slowly corrode internal engine surfaces over months of inactivity. Top off coolant, brake fluid, and other fluids to their proper levels, and consider checking coolant concentration if storing through a cold season in an unheated space.
The battery: disconnect or tend it
- Disconnect the negative terminal for storage over roughly two months if you don't have a tender — this stops parasitic drain entirely.
- A smart battery tender (not a basic trickle charger) is the better option if you can leave it connected, since it maintains charge without overcharging.
- Store a fully removed battery in a cool, dry place off direct concrete floor contact if it will be out of the car for an extended period.
Tires: the most overlooked long-term storage risk
A tire that sits in one position for months develops a flat spot where the weight of the car compresses the rubber at that contact point — this can become permanent after roughly a month or more of stationary storage in some tires, especially older ones. Inflating tires slightly above the normal pressure (check tire max rating) helps somewhat, but for genuinely long storage (six months or more), raising the car on jack stands to take weight off the tires entirely is the most reliable prevention.
Pest-proofing
Rodents nesting in an engine bay or exhaust system over a storage period can chew through wiring insulation, causing expensive electrical faults or even fire risk. Stuff the exhaust pipe and air intake opening with fine steel wool or a dedicated mesh cover, and consider rodent deterrent packs or traps in the storage space.
Covering and the storage environment
- Wash and fully dry the car before covering it — dirt and moisture trapped under a cover accelerate paint and corrosion issues.
- Use a breathable, fitted car cover rather than a plastic tarp, which traps moisture against the paint.
- Store indoors if at all possible; a garage or dedicated storage unit protects against UV, precipitation, and temperature swings far better than an outdoor cover alone.
- Crack a window slightly (in a secure, indoor storage setting) to reduce interior humidity buildup and musty odors.
Bringing it back out
Reconnect or fully charge the battery, check tire pressure and inspect for cracking or dry rot before driving, and change the oil again if it sat for many months even though you changed it before storage — moisture can still accumulate. Start the engine and let it idle briefly before driving, and take the first drive gently to make sure brakes, steering, and suspension feel normal after the inactive period.
Frequently asked questions
How long can a car sit without being driven before problems start?
Do I need to disconnect the battery for long-term storage?
Should I leave the parking brake on during long-term storage?
Is fuel stabilizer really necessary?
What's the best way to protect tires during long storage?
Sources & further reading
- AAA — Long-Term Vehicle Storage Guidance
- Consumer Reports — Storing a Car Long-Term
- U.S. Department of Energy — Fuel Storage and Degradation
Figures, prices and policy details were current at the last-updated date above. Automotive pricing, incentives and regulations change frequently — verify time-sensitive details with the linked primary sources. Read our editorial policy and fact-checking standards.
