How many kilometers should run-flat tires be replaced?
4 Answers
Under normal usage, they are typically replaced between 40,000 to 50,000 kilometers, and must be replaced after 6 years regardless of mileage. Below is more information about run-flat tires: 1. Concept: Run-flat tires, technically known as "Self-Supporting Run-flat Tires" with the English abbreviation RSC. The sidewall of an inflated tire is the main part supporting the vehicle's weight, especially for tires with a larger aspect ratio (the ratio of tire height to width). These sidewalls are very "thick," and severe "tire blowouts" usually cause the sidewall to rupture instantly, leading to an immediate loss of support and a sudden change in the vehicle's center of gravity. 2. Advantages: The greatest advantage of run-flat tires is that in the event of a tire leak, even if the air pressure is completely lost, the vehicle can continue to drive at speeds up to 80 km/h without the immediate need to replace the tire.
Last time before a long trip, I specifically went to have my tires checked. The technician said run-flat tires don’t actually have a fixed replacement mileage. The raised block pointed to by the triangular mark on the tire sidewall is the wear indicator – once it’s worn flat, it means the grip is compromised. When I mainly used the car for city commuting and reached 70,000 km, the tire sidewalls were already covered in fine cracks, and I could clearly feel slipping when cornering in the rain. Rubber aging is more dangerous than tread wear, especially in high summer temperatures. Last year, my friend had a nail puncture on the highway causing air loss; the run-flat tire allowed him to drive to the service area, but the steel belt layer was deformed – such tires must be replaced. It’s recommended to check the tread depth every 5,000 km; if it’s below 1.6 mm, it’s time to replace them. Tires older than five years should be replaced regardless of mileage.
Replacing run-flat tires depends on the actual condition. I've seen ride-hailing drivers change them after 120,000 km, while luxury cars may have bulges and become unusable after just 30,000 km. The key is regular inspections: check the tread monthly for nails, and beware of bulges or cracks on the sidewalls, which are dangerous. Get tire pressure and dynamic balance checked quarterly at a shop. Recently, a driver didn't notice small stones stuck in the tire, leading to rusted steel belts and a blowout. Run-flat tires are especially vulnerable to corrosive liquids, and tire wax from car washes can accelerate aging. If you often drive on construction sites or rough roads, consider replacement around 50,000 km. Remember the production date code on the tire sidewall—replace them outright after six years.
I've driven for 25 years and replaced over a dozen sets of run-flat tires. For household vehicles, it's common to change them every 50,000 to 80,000 kilometers, but it depends on driving habits. Frequent hard braking wears out front tires faster—when the tread pattern in the center becomes flat, it's time to replace them. Once I hit a pothole without slowing down, and the rim cracked the tire sidewall. Run-flat tires have thick but brittle sidewalls, making them more prone to cracking in cold winter temperatures. A repair shop mechanic taught me to check the raised rubber blocks in the tread grooves—when they wear down to the groove bottom, it means only 1.6 mm of tread remains. Key point: Always replace both tires on the same axle, otherwise, grip balance will be compromised.
