Tyre Advice

Understanding Tyre Speed Ratings and Load Indices

Glasgow Mobile Tyre Guys
5 September 20254 min read

Fitting tyres with the wrong speed rating or load index is illegal and dangerous. Here is a clear guide to what these numbers mean and why they matter.

When choosing replacement tyres, matching or exceeding the speed rating and load index specified for your vehicle is a legal requirement. Fitting tyres below the manufacturer's prescribed ratings can invalidate your motor insurance, may result in an MOT failure, and could compromise the structural safety of the tyre under load.

The speed rating is represented by a letter at the end of the tyre size code. Common ratings include H (210km/h), V (240km/h), W (270km/h), and Y (300km/h). You must fit tyres with a speed rating at or above your vehicle's original specification — fitting a lower-rated tyre is not permitted on UK public roads.

The load index is a two- or three-digit number that indicates the maximum weight each individual tyre can safely support. A load index of 91 equates to 615kg per tyre, while 98 equates to 750kg. Your replacement tyres must carry a load index equal to or greater than the originals to ensure the vehicle can be loaded safely.

If you are unsure which speed rating or load index your vehicle requires, Glasgow Mobile Tyre Guys can identify the complete specification from your registration number. We supply only tyres that meet or exceed your vehicle's requirements, so you can drive with full confidence in the safety and legality of your fitment.

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tyre speed rating explainedtyre load indextyre specification Glasgow

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