How to Read Your Tyre Sidewall (Size & Age)
The numbers on your tyre tell you its size, ratings and age. A Cranbourne West specialist decodes them.
Decoding the markings
A code like 225/45 R18 95Y means: 225 = width in mm, 45 = profile (sidewall height as % of width), R = radial, 18 = rim diameter in inches, 95 = load index, Y = speed rating. Always replace with the size and load/speed rating your car specifies (on the placard).
Fitting a lower load or speed rating than specified is unsafe and a roadworthy issue.
Checking the age
The four-digit DOT code shows the week and year of manufacture (e.g. 3220 = week 32 of 2020). Tyres degrade with age even with good tread — rubber hardens and cracks — so an old tyre with plenty of tread can still be unsafe and is worth replacing after several years.
We check size, ratings, age and condition at every service and advise honestly.
We’ll take care of it
Prefer to leave it to a specialist? We look after all of this as part of a service or a quick check — with honest advice on what your car actually needs, not what sells.
Book online in 60 seconds or call a Cranbourne West specialist on 03 8782 0711.
How to Read Your Tyre Sidewall (Size & Age) — FAQ
Width/profile/rim, then load index and speed rating — e.g. 225/45 R18 95Y. Match your car’s placard.
The four-digit DOT code = week and year (e.g. 3220 = week 32, 2020).
Yes — rubber hardens and cracks with age and can be unsafe despite tread.
Only the specified size and load/speed rating — lower ratings are unsafe and a roadworthy issue.
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