How to Determine if a Tire is a Run-Flat Tire?
3 Answers
Tires can be identified as run-flat by checking for special symbols on the sidewall specifications. Different manufacturers use different markings. If there are special symbols following the tire sidewall specifications, it is a run-flat tire; otherwise, it is a regular tire. Below is an introduction to run-flat tires: 1. Run-Flat Markings: Pirelli's run-flat marking is R-F, Continental's is SSR, Bridgestone's is RF, Michelin's is ZP, and Dunlop's is RF. 2. Sidewall: Run-flat tires have thicker sidewalls compared to regular tires, which have relatively thinner sidewalls. Regular tires do not have special letter markings on the sidewall.
To determine if a tire is a run-flat, the most reliable method is to check the markings on the tire sidewall. Run-flat tires are imprinted with special symbols, such as combinations of letters like RFT, ROF, SSR, or ZP. These vary by brand but all indicate run-flat technology. Additionally, if you feel the sidewall, it will be exceptionally thick and rigid—pressing hard won't make it budge—due to reinforced structures that support the vehicle's weight. Another way is to check the vehicle's configuration: if the car doesn't come with a spare tire and instead has an air pump and tire repair kit in the trunk, it's likely equipped with run-flat tires. When I last changed tires, I did some research and found that regular tires have much thinner sidewalls and provide a noticeably bumpier ride. By the way, if the tire model includes the letters XL, it means it's reinforced, but not a run-flat—be careful not to confuse the two.
I usually focus on two areas when inspecting tires: the sidewall markings and tread depth. Run-flat tires will always have a shield-shaped symbol or the letters RSC on the sidewall, which is a standardized manufacturer marking. They feel much harder than regular tires, especially the thickness of the rubber layer, which is almost twice that of standard tires. Try pinching them with your fingers - regular tires will deform when pinched, while run-flats remain rigid. Another simple method is checking the weight - due to their construction, run-flat tires are significantly heavier, with a single tire weighing 2-3 kg more. When changing tires, pay attention to the model description near the production date; proper run-flat tires will be marked with "runflat" or "airless" indicators. I remember using these methods to help a friend inspect a car last time, and they worked really well.
