If you drive a BMW, a MINI or one of several Mercedes models, there’s a fair chance you’re on run-flat tyres without ever having chosen them. They’re the reason many of these cars have no spare wheel at all. They’re also why some owners get a surprise when it’s time to replace them.
Here’s what you’re paying for, and when it’s worth it.
Not sure whether your car has them? Look for one of the codes below on the sidewall, or check the boot: a car with no spare wheel and no space for one is almost always on run-flats.
01How a run-flat works
A normal tyre is held up by the air inside it. Lose the air and the sidewalls fold, the rim drops onto the rubber, and you’re stopping wherever you happen to be, safe spot or not.
A self-supporting run-flat has much stiffer, reinforced sidewalls that can carry the weight of the car for a while with no pressure at all. The usual figure is around 80 km at up to 80 km/h, enough to get off the motorway and to a fitter or home. Your car’s handbook has the exact numbers for your model, and they’re worth checking.
Because the tyre keeps its shape, you may not feel a puncture at low speed. That’s why cars on run-flats always have a tyre pressure monitoring system. If the warning light comes on, believe it.
Can a punctured run-flat be repaired? Sometimes. If you got to a fitter quickly and the tyre wasn’t driven far without air, a small hole in the tread can be repairable, depending on the tyre maker’s rules. The fitter has to take the tyre off the rim to look at the inside. Any sign of damage on the inner sidewall, and it’s a replacement.
02The markings to look for
Every brand has its own name, which doesn’t help. The common ones:
- RFT: Bridgestone (Run Flat Technology)
- ROF: Goodyear and Dunlop (RunOnFlat)
- SSR: Continental (Self-Supporting Runflat)
- ZP: Michelin (Zero Pressure)
- r-f or Run Flat: Pirelli
- RSC: printed on run-flats approved for BMW
On our product listings, run-flat tyres are tagged in blue so you can spot them at a glance. The size part of the code works the same as on any other tyre; if you need a refresher, see how to read a tyre size.
03The good and the not so good
The case for them is strong in this part of the world. Nobody wants to change a wheel on the shoulder of a busy highway in 45-degree heat, with traffic passing a metre away. With a run-flat you keep steering control when a tyre goes, and you drive to somewhere safe.
The downsides are real too:
- The stiffer sidewalls make for a firmer ride, especially over expansion joints and speed bumps.
- They usually cost more than the equivalent standard tyre.
- Once a run-flat has been driven any distance without air, most makers say it shouldn’t be repaired, only replaced.
- There are fewer models to choose from in each size.
04Can you switch to normal tyres?
You can, and some owners do it for comfort. Just think it through. The car was designed around run-flats: often there’s no spare, no jack and nowhere to put either, and the suspension was tuned with stiff sidewalls in mind. If you switch, carry a good sealant kit and a compressor, accept that the handling will feel a little different, and make sure every tyre on the car matches.
Our honest advice: on cars that came with run-flats, stay with them, and pick one with the car maker’s approval mark where you can. On a BMW that’s the star (★). Our guide to car-maker tyre markings explains what those codes mean.
05Don’t mix them
Never fit a run-flat and a standard tyre on the same axle. Ideally keep all four the same type and the same model, because the two behave very differently when a tyre loses pressure, and that’s exactly the moment you need the car to be predictable.
To see the sizes your car takes, look it up on our tyres by car pages, for example the BMW X5 or the Mercedes-Benz C-Class. Run-flat options from Bridgestone, Pirelli and Continental are listed with the fitted price, and if your size isn’t showing in run-flat, ask us on WhatsApp and we’ll check what we can get.