Decoding the Size Code

Take a tyre marked 205/55 R16 91V. The 205 is the section width in millimetres measured across the widest point of the tyre. The 55 is the aspect ratio — the sidewall height as a percentage of the width, so 55% of 205mm = about 113mm of sidewall. R means Radial construction (standard for all modern road tyres). 16 is the rim diameter in inches that the tyre fits. This exact size code must be matched when replacing; using a different size affects your speedometer, ABS, and safety systems. If in doubt about your correct size in Bradford, Motorway Mobile Tyres can look it up using your registration plate.

Load Index and Speed Rating

The 91V at the end of the size code gives you the load and speed capability. 91 is the load index — referring to a lookup table, 91 corresponds to a maximum load of 615 kg per tyre. Never fit a tyre with a lower load index than originally specified for your vehicle. V is the speed rating — V-rated tyres are tested to 149 mph continuously. Other common speed ratings on Bradford roads include H (130 mph), W (168 mph) for performance cars, and T (118 mph) for some older vehicles. Always match or exceed the original speed rating; fitting a lower-rated tyre on a vehicle capable of higher speeds is illegal.

Other Important Markings

Look for the "Rotation" arrow if your tyre is directional — these tyres must be fitted facing the correct direction of travel. If the arrow is present, make sure our Bradford technician (or any fitter) orients the tyre correctly; a reversed directional tyre provides significantly reduced wet-weather performance. The "XL" or "RF" marking indicates a reinforced or extra-load tyre for heavier vehicles and loads. "M+S" (Mud and Snow) markings indicate some cold-weather suitability, but for full winter certification, look for the Three-Peak Mountain Snowflake symbol. The manufacture date is also on the sidewall — four digits in an oval, e.g. "2319" means the 23rd week of 2019.