Run-flat markings (RFT, ROF, ZP, SSR)
The tire is a run-flat: its reinforced sidewalls carry the car for a limited distance after it loses air. Each maker uses its own letters: RFT, ROF, ZP, SSR and others.
How to read it
Pirelli’s guide lists RFT (Run Flat Technology), SSR (Self Supporting Run Flat) and ROF (Run On Flat) as acronyms that show a tyre is a run-flat, and says Pirelli’s own are marked Run Flat. Goodyear’s are marked RunOnFlat or ROF, and some older ones EMT, for Extended Mobility Technology. Michelin’s are ZP, for Zero Pressure, and Bridgestone calls its technology Run-Flat Technology (RFT). Continental lists a Self-Supporting Run-flat marking. Pirelli also says run-flat tyres carry an ISO symbol: the letters RSC (Run Flat System Component) in a circle.
Also searched as: RFT, ROF, run flat tire, SSR, ZP.
What each marking means under the standard that defines it. This page describes markings; it doesn’t advise on choosing, fitting, inflating or replacing tires.
How far, in the makers’ words
Bridgestone says its run-flats keep going after a loss of pressure for up to 80 km (50 miles) at up to 80 km/h (50 mph). Michelin gives the same figures for its ZP tires, and Goodyear says at least 80 km (50 miles) at up to 80 km/h (50 mph). Bridgestone’s page says the manufacturer’s specifications give the maximum distance and speed for a particular tire.
Two kinds of run-flat
Bridgestone describes two systems: self-supporting, where reinforced sidewalls carry the load, and support ring, where a ring under the tread does. It says every run-flat may only be used on a vehicle with a tire pressure monitoring system, because without one a driver might not know the tire is underinflated; that system’s dashboard light is the tire pressure warning light.
More tire sidewall markings
Browse symbols drawn with curves and waves or letters and numbers.
Sources
- Run flat tyres: what they are and how to identify them, Pirelli (UK), How to identify run flat tyres
- What Are Run Flat Tyres?, Goodyear (UK), How to identify
- Learn About Run Flat Tires, Michelin (Middle East), Run flat tires
- Run-flat tyres: keep on going, Bridgestone Australia, Run-flat tyres
- What Are Run Flat Tires?, Bridgestone Americas, What are run flat tires?
- Tire markings, Continental Tire (Canada), Additional markings
Last reviewed September 29, 2026 by Rory Hansen. How we research