The numbers on your tyre sidewall give you the tyre size you need to order. If you
look at the image below each number relates to a different measurement

225 - gives you the width of the tyre in millimetres, 225mm in this example.
40 – expresses the height of the tyre sidewall as a percentage
of the width of the tyre.
R – means the tyre is of radial construction.
18 - in this example is the diameter of the tyre’s inner rim in inches.
87 - is the load rating - this shows what weight each tyre is capable of bearing
– in this example 545kg. You can check this using the Tyre Load Rating Table below:
Tyre Load Rating Table

W - tells you what speed rating the tyre has in this example it
means that the tyre is capable of reaching speeds of 168mph. The lower down the
alphabet the speed rating is the lower the speed that tyre is capable of doing.
It is vital that you check the appropriate speed rating for your vehicle and that
you do not purchase a tyre with a lower speed rating as this could invalidate your
insurance and cause serious safety issues at high speed.
The table below will help:
Tyre Speed Rating Table

If you need to know anything else drop us an email to
hello@cartyres.com