Run-flat tyres

Worried about getting a puncture,  you might want to consider run-flat tyres next time you change your car.

Run-flat tyres have either a reinforced sidewall or additional internal structure to provide partial support to the tyre in a deflated condition and are being offered by more and more manufacturers on new cars.

The vehicle handbook will give details but in general deflated tyres should be capable of at least 50 miles (range can vary with vehicle load) at speeds up to 50 mph. Tyres should be renewed or repaired as soon as possible following a puncture.

The TPMS will probably need to be reset after a new tyre has been fitted. Check the handbook for details.


Run Flat Tyre Markings

Brand Run Flat Tyre Descriptions
Bridgestone RFT (Run lat Tyre
Continental SSR (Self Supporting Run Flat
Dunlop DSST (Dunlop Self Supporting Tyre)
Goodyear EMT (Extended Mobility Tyre)
Michelin ZP (Zero Pressure)
Pirelli Tyre identified as a “Run Flat” tyre

Fitment Codes

Fitments codes are stamped on the tyre to help identify any special features making it better suited for certain driving styles or vehicles

Code Description Code Description
RE Reinforced C1 Chrysler Fitment
RF Reinforced RO & AO Audi
XL Extra Load G1 Various Fitment
MS Mud / Snow A Renault Espace 4 Fitment
AS Asymmetric * BMW Fitment
N0 Porsche Fitment MO Mercedes Fitment
N1 Porches Fitment J Jaguar Fitment
N2 Porches Fitment 6PR 6Ply
N3 Porches Fitment 8PR 8Ply
B Bentley/Continental GT Fitment MC1 MACLAREN FITMENT

Tyre Wear

  • Driving style – aggressive cornering

and braking increases wear

  • Position front tyres wear faster because of

movement through steering & tyres on front

  • Speed – high speed driving increases

temperature and wear

  • Load – excess load increases wear
  • Pressure – under inflation and over inflation

can both increase wear

Alignment – tyres will wear quickly and unevenly

if wheel alignment is wrong of if there is excessive

wear in suspension components like shock absorbers


Car Tyres Explained

Which are the right tyres to suit you, your budget, your vehicle, your expectations and your safety. The first thing to remember when you have a tyres fitted – regardless of the make or style – is that they will undoubtedly make the car ‘feel’ different even if they’re exactly the same type of tyre fitted again. It takes a few miles to settle in to new tyres and to understand the subtle differences in handling and cornering that new tyres provide.