Guides
Plain guides with worked examples: reading a tyre size, choosing an equivalent size, wheel offset, winter tyres and more.
How to read a tyre size, using 205/55 R16 91V as an exampleWhat each part of a sidewall code such as 205/55 R16 91V means, explained with a worked example.The door label: where is your car's factory tyre size shown?How to read the tyre label on the driver's door, why you shouldn't trust the tyres currently fitted, and other ways to find the factory size.Equivalent tyre sizes and the ±3% ruleWhy the overall diameter difference should not exceed 3% when fitting a tyre size other than the factory size, with worked examples.Tyre speed rating and load index tableTables showing how many kilograms each tyre load index number means and how many km/h each speed rating letter stands for.How to read wheel sizes: a guide to 7Jx17 ET45 5x112Wheel width, diameter, ET (offset), PCD (bolt pattern) and centre bore explained, plus what to check when choosing wheels for your car.How far does a wheel ET (offset) difference move the wheel?A step-by-step calculation of how far a wheel moves inwards and outwards when you fit a wheel with a different width and ET value.What should your tyre pressure be? Where is the correct value shown?Where to find your car's correct tyre pressure, bar and psi units, and how pressure changes with a loaded car and in winter.When should you fit winter tyres? M+S vs 3PMSFWhy winter tyres make a difference below 7 degrees, how M+S differs from the snowflake symbol, and how to switch at the right time.What tread depth should your tyres have? Legal limit and measuringThe legal minimum tyre tread depth, how to use the wear indicator and how to measure tread depth at home with simple methods.How to read a DOT code: a tyre's production date and ageHow to read the week and year of manufacture from the last four digits of the DOT code on a tyre sidewall, and why tyre age matters.How to read the EU tyre labelWhat the fuel efficiency, wet grip and noise classes on the label of a new tyre mean.Tyre rotation, balancing and wheel alignment: when and why?What tyre rotation, wheel balancing and wheel alignment are, when they should be done and how they affect tyre life.