The short answer for how long you can drive on a flat tire is… at a speed above 35mph, you could cause irreversible damage in under one mile of driving.
To properly answer the question “how long can I drive on a flat tire” depends two things: How flat is the tire (the psi) and what type of tire is on your car.
What is considered a flat tire?
A flat tire is considered anything under 20 psi (pressure per square inch). When you are running your tire under 20 psi, the sidewalls of the tire will get very hot, the rubber will breakdown, the tire could come off the rim on a sharp turn, and this will ultimately lead to a tire blowout.
What type of tire does my car have?
Most passenger cars and trucks are equipped with one of the following three types of tires: Run Flat Tires, PAX Tires, or standard passenger tires. You will be able to find which tire your vehicle has inside your owner’s manual. The tire designs are explained below.
Run Flat Tires (7% of all cars and trucks)
You typically find run flat tires on sports cars and high end luxury vehicles. These tires allow for the driver to get a “flat tire” (losing all of the air inside the tire) but still drive safely up to 55 mph.
The tires are able to support the weight of the vehicle due to the heavy duty construction on the tire. These tires are made with extra metal sandwiched between layers of rubber.
PAX Tires (3% of all cars and trucks)
There are a few vehicles that are equipped with PAX tires. A few examples of vehicles that used the PAX tires are the Honda Odyssey and the Toyota Sienna minivan. The PAX run-flat tire system that utilizes a special type of rim with a semi-rigid ring installed in the center of the rim. When the tire goes flat, the rigid ring is there to support the tire from completely folding over onto itself. This PAX style tire allows the driver to continue to drive at a reduced rate of speed until the tire can get repaired or changed.
Standard Passenger Tires (90% of all cars and trucks)
90% of the vehicles on the road are equipped with standard passenger tires. These tires don’t stand up well when they are driven on a flat tire. Most tires are made to drive with no less than 20 psi and no more than 50 psi at any time.
Also since 2008, all passenger cars sold in the US come standard with a Tire Pressure Monitor System (TPMS) in order to alert the driver of a flat tire. If you have a Tire Pressure Monitor Light on, click here.
Depending on the speed that you are driving at the time of a flat tire, you could cause irreversible damage in under one mile of driving. You should always have a technician inspect your tire for internal damage before just repairing it. The damage may not always appear on the outside of the tire.
Written By Eric Sevim – ASE Master Certified Mechanic
A+ Japanese Auto Repair, Inc. |
780 Industrial Road
San Carlos CA 94070