How Long Can a Car Sit Without Being Driven?

Most experts recommend driving your car at least once every one to two weeks for 15 to 30 minutes. Go longer than that, and problems start stacking up. Whether you’re heading out of the country, storing a second car for the season, or just not driving much lately, here’s what happens to a car that sits, and what to do about it.

Here’s what actually happens over time

There’s no single magic number, but here’s a practical timeline of what starts going wrong:

• 2 weeks: Battery charge starts dropping significantly from parasitic drain (your car’s computers, clock, and alarm never fully sleep).
• 1 month: Gasoline begins to degrade and can leave varnish deposits in the fuel system. Tire flat spots may begin forming. Brake rotors can develop surface rust.
• 3 months: Oil loses some of its protective properties even without miles on it. Coolant and brake fluid may absorb moisture. Seals can dry out.
• 6+ months: Fuel has likely gone stale, tires may have permanent flat spots, and pests may have moved in. Engine problems become a real possibility.

Two weeks is roughly the threshold where you shift from “fine” to “starting to cost you something.”

The problems that develop when a car sits idle

Some of these start sooner than you’d expect. Here’s what to watch for.

Dead battery from parasitic drain

This is almost always the first thing to fail. Even when your car is off, small systems keep drawing power: the alarm, the keyless entry module, the clock, and any connected devices. That’s called parasitic battery drain, and it adds up. A typical car battery can go dead in two to four weeks without driving. Older batteries or cold weather can cut that window even shorter.

Tire flat spots from sitting

Tires aren’t rigid. The part touching the ground bears the full weight of the car and can deform over time. After a few weeks, you may feel a thump or vibration when you start driving again. Usually, flat spots work themselves out after a few miles once the tires warm up. But if your car sits for months, those flat spots can become permanent, meaning you’ll need new tires.

Fluid degradation

Car fluids don’t last forever, even without driving:

• Gasoline starts degrading after about 30 days and can clog fuel injectors or gum up the fuel system.
• Engine oil breaks down over time, not just miles, and loses its ability to lubricate properly.
• Brake fluid absorbs moisture from the air, which lowers its boiling point and can cause corrosion inside the brake lines.
• Coolant can degrade and become acidic, which slowly eats at metal components.

Rust and corrosion

Brake rotors are especially vulnerable. They can develop surface rust within days of sitting, especially in humid conditions. That rust usually scrubs off on the first few brake applications, but deep corrosion from sitting for months is a different story. The exhaust system, fuel tank, and undercarriage are also at risk if the car is stored outdoors or in a damp environment.

Pest intrusion

Mice, rats, and squirrels love a parked car. They’ll chew through wiring, nest in the air filter, and cause damage that can run into thousands of dollars. This is a bigger risk in garages with outdoor access, or if you’re storing the car near fields or wooded areas.

Car storage checklist: what to do before parking long-term

If you know the car is going to sit for more than a month, take these steps before you park it:

1. Add a fuel stabilizer. Pour it into a full tank of fresh gas. Fuel stabilizer prevents gasoline from breaking down and leaving deposits. Run the engine for a few minutes so it circulates through the system.
2. Use a battery maintainer (trickle charger). A battery maintainer keeps the charge topped off without overcharging. It’s one of the easiest ways to make sure the car starts when you come back.
3. Inflate tires to the high end of the recommended range. This helps reduce flat-spotting. Check the door jamb sticker for your car’s recommended pressure.
4. Change the oil if it’s due soon. Old oil sitting in the engine can cause corrosion. Fresh oil is better for storage.
5. Choose your storage location wisely. Indoors is always better than outdoors. A climate-controlled space is ideal. If you’re storing outside, invest in a quality car cover.
6. Leave the parking brake off. Brake pads can fuse to rotors if the parking brake is left engaged for months. Use wheel chocks instead.
7. Plug the exhaust pipe and air intake with steel wool or a rag. This keeps pests out. Just make a note so you remove them before starting.

Electric vehicles sitting idle: different rules, different risks

EVs have some advantages when it comes to storage (no gasoline to go stale, no oil to degrade), but they have their own set of considerations that most storage guides skip entirely.

High-voltage battery charge targets

For long-term storage, most EV manufacturers recommend keeping the main battery pack between 50% and 80% state of charge. Storing at 100% for extended periods can cause battery degradation. Storing near 0% risks deep discharge, which can permanently damage the pack. Tesla specifically advises against storing below 20% and recommends plugging in on a low charge setting if the car will sit for weeks.

The 12V auxiliary battery

Here’s the one that surprises most EV owners: EVs still have a small 12V auxiliary battery that powers things like the door locks, lights, and onboard computers. This battery drains just like a traditional car’s, and it can die if the car sits unplugged for weeks. A dead 12V battery can prevent the car from waking up at all, even if the main pack is fully charged. The fix is the same: a battery maintainer or keeping the car plugged in.

EV-specific storage tips

• Keep the main battery between 50–80% charge during storage.
• If possible, leave the car plugged in on a low charge setting so it can maintain itself.
• Check your manufacturer’s specific guidance – Tesla, Rivian, and others publish storage recommendations in their owner’s manuals or apps.
• Tire flat spots and brake rotor rust apply to EVs just as much as gas cars.
• Software updates may still run during storage if connected to Wi-Fi, which is generally a good thing.

What happens to your car insurance when the car sits?

If your car isn’t moving, you probably don’t need full coverage. Liability insurance covers damage you cause while driving — not much use if you’re not driving. But a parked car can still be stolen, catch fire, flood, or get hit by a falling tree. That protection is worth keeping.

What to consider:

• Some insurers offer comprehensive-only coverage that drops liability and collision (and their premiums) while keeping protection for theft, fire, and weather damage.
• If you have a car loan, your lender will likely require full coverage regardless.
• Canceling your policy entirely can trigger a lapse-in-coverage surcharge when you reinstate it.

Check with your insurer about your options before making any changes — and when you’re ready to drive again, make sure to add liability and collision coverage  back before hitting the road.

Before we go

A car sitting for a few weeks isn’t a disaster. But a car sitting for months without preparation can rack up serious repair bills before you ever turn the key. Stabilize the fuel, maintain the battery, inflate the tires, and store it somewhere dry. Do those four things, and you’ll come back to a car that actually starts.

And if you’re storing a car long-term, it’s worth a quick look at your coverage too. Paying for full insurance on a car that doesn’t move is money that doesn’t need to leave your pocket.

Car sitting without being driven FAQs

A few quick words, because we <3 our lawyers: This post is general in nature, and any statement in it doesn’t alter the terms, conditions, exclusions, or limitations of the policies issued, which differ according to your state of residence. You’re encouraged to discuss your specific circumstances with your own professional advisors. The purpose of this post is merely to provide you with info and insights you can use to make such discussions more productive! Naturally, all comments by, or references to, third parties represent their own views, and Lemonade assumes no responsibility for them. Coverage may not be available in all states. Please note that statements about coverages, policy management, claims processes, Giveback, and customer support apply to policies underwritten by Lemonade Insurance Company or Metromile Insurance Company, a Lemonade company, sold by Lemonade Insurance Agency, LLC.  The statements do not apply to policies underwritten by other carriers.