145 is the tread width in millimetres, 80 is the sidewall height as a percentage of the width, and R15 means radial construction for a 15-inch wheel. When buying, also match the tyre’s load index and speed rating to what your car manufacturer specifies.
Check the tyre size on your current sidewall, then verify it against the tyre placard (usually on the driver’s door shut) or your handbook. If 145/80 R15 is listed as an approved size, choose the same size and the correct load and speed rating.
Use the ratings printed on your existing tyres or listed on the vehicle placard as your baseline. You can move to a higher load index or speed rating if needed, but avoid going lower unless your manufacturer explicitly allows it.
All-season can suit 145/80 R15 if you drive year-round in mixed UK conditions and want one set for wet roads and colder months. If you regularly face ice or heavy snow, consider winter tyres instead, and if you prioritise warm-weather performance, choose summer tyres.
Only switch if your vehicle manufacturer lists an alternative size as approved, as changing width or profile can affect rolling radius, speedometer accuracy and clearance. If you are unsure, stick with 145/80 R15 and select the correct load and speed rating for your car.
