how long can a car sit on a flat tire

[VanDallas]

A car should not sit on a flat tire for more than 24 hours. Prolonged parking on a completely deflated tire can cause permanent, irreparable damage not just to the tire itself, but also to the wheel rim and even the vehicle's suspension components. The primary risk is damage to the tire's sidewall, which is not designed to support the vehicle's weight without air pressure.

The moment a tire goes flat, the entire weight of the car rests on the sidewall and the wheel rim. This crushes the sidewall between the rim and the ground, compromising its structural integrity. The rubber can develop cracks, and the internal fabric cords can break. This damage is often invisible from the outside but creates a weak spot that can lead to a blowout later, even after the tire is reinflated.

Beyond the tire, the metal wheel rim is also at risk. On a hard surface, the rim can become bent or cracked. If the car is parked on softer ground, moisture can seep in and cause the rim to rust where it contacts the ground. Another critical concern is the tire bead—the edge of the tire that seals against the rim. The weight of the car can break this seal, making it impossible to reinflate the tire without professional equipment.

The following table outlines the potential consequences over time:

Duration on Flat Tire	Primary Risks & Likely Outcomes
Less than 24 hours	Possible reversible sidewall compression. Rim damage is unlikely on a smooth, level surface. The tire may still be salvageable.
1-7 days	High probability of permanent sidewall damage (broken cords). The tire bead may lose its seal. Risk of rim deformation or rust begins to increase significantly.
Over 1 week	The tire is almost certainly destroyed and unsafe to use. The wheel rim is likely damaged, requiring repair or replacement. Suspension components may be under undue stress.

If you find your car with a flat, the best practice is to move it as little as possible to a safe location and place the spare tire immediately. If you cannot change it yourself, call for roadside assistance. Towing the car is a much cheaper alternative than replacing a set of rims and tires.

[McSabrina]

Don't push it. I left my old sedan on a flat in the driveway for maybe five days last winter. When the tow truck guy finally came, he just shook his head. The tire was shot—permanent creases in the sidewall—and the rim had a slight bend. He said it's like bending a paperclip back and forth; the metal gets weak. Get it on a jack stand or a spare as soon as you can. A day or two might be okay, but anything longer is asking for trouble and a bigger bill.

[ChristianDella]

Think of the tire sidewall like the bones in your foot. Standing on it with no support (air pressure) for a long time will break it. The damage might not be visible, but the internal structure is compromised. This isn't just about the tire; the wheel rim is taking a beating too. It's designed for rolling, not for being a stationary load-bearing point on concrete. The cost of a tow is far less than a new tire and a rim repair. Address it within a day to be safe.