Tyre Dimension Information
Whether you want to use wider tyres on your standard alloys or match the original rolling radius with your new alloys, the data is here.
Mod difficulty:
Mod Credit: various

 Tyre Calculator

There are very good online tyre calculators already so I don't think I need my own.

Click here

Tyre Width Information

Depending on the width of the alloy, you have a range of tyre widths you can choose.
It is important not to exceed the minimum or maximum widths.
Rim width Minimum tyre width Ideal tyre width Maximum tyre width




3.5 inches 125 mm 135 or 145 mm 155 mm
4.0 inches 135 mm 145 or 155mm 165 mm
4.5 inches 145 mm 155 or 165mm 175 mm
5.0 inches 155 mm 165 or 175 mm 185 mm
5.5 inches 165 mm 175 or 185 mm 195 mm
6.0 inches 175 mm 185 or 195 mm 205 mm
6.5 inches 185 mm 195 or 205 mm 215 mm
7.0 inches 195 mm 205 or 215 mm 225 mm
7.5 inches 205 mm 215 or 225 mm 235 mm
8.0 inches 215 mm 225 or 235 mm 245 mm
8.5 inches 225 mm 235 or 245 mm 255 mm
9.0 inches 235 mm 245 or 255 mm 265 mm
 
Adapted from Pneus-Online

Tread Depth

Taken and adapted from Nick's Tyres Essex.

The legal minimum tread depth for car tyres in European is 1.6mm throughout a
continuous band comprising of the central three quarters of the breadth of tread
and round the entire outer circumference of the tyre.

Most car tyres have tread wear indicators, usually at least six small ribs across
the bottom of the main tread grooves, and when the tread surface becomes level
with these ribs the tyre is at the legal limit and must be replaced.

Simple and cheap gauges are widely available to give an acceptable guide to tread depth.

One of the features of tyre tread pattern design is to give good grip in wet conditions. Generally speaking, available grip reduces as the tyre wears or as the road surface water depth increases.
You should reduce speed in such conditions.

Nicks Tyres is in Brentwood and Chelmsford and is my local tyre shop.
They are very helpful so if you live in the area, check them out for their services.

Tread Wear Indicators

Here is a nearly new tyre. Inside the tread, across the middle 75%,
dotted around the circumference of the tyre are raised indicators.



And this is an old tyre. You can see that the tread wear indicators are flush
with the rest of the tyre face meaning that the tyre is too worn and is illegal.



Tyre Calculator

There are very good online tyre calculators online so I don't think I need my own.

Click here
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