Metric size tyres
quite confusing and puzzling tyre sizes that some vehicles are fitted
with are called metric sizes a good example of a metric size is:
This size is one off the sizes found as original fitment on some of the old BMW 525.
The cross section of this tyre measures 230mm, the
sidewall height is 55, the speed rating is ZR and the rim size as in the
diameter of the wheel is 390mm.
Metric wheels were limited to a few cars only namely a
BMW, Ferrari, and a few others. All these cars had wheels that were
essentially in metric (mm) i.e. a 390mm, 360 mm etc. The difference was
the standard rims came in exact inches i.e. 14 ", 15" and 16". Metric
sizes also had different or odd width dimensions i.e.| 220, 230, 240
etc. Normal sizes the section width usually were 225, 235, 245 sizes go
up 10mm and start and would never be 230, or 220. The tread designs
were all similar or largely the same and very few manufacturers actually
made these metric sizes most popular were Dunlop and Michelin. Metric
wheels and tyres were never going to feature on every car as they never
did become popular. The tyres themselves were quite stiff and were
intended to withstand punctures and run as a run flat, that in itself is
a very long debate with many different opposing views.
Metric tyres are quite hard to find the only company
still making them are Dunlop and even their stock is often limited.
Metric sizes no longer feature on new cars and it just as good as the
price of an on off size was very expensive. Today drivers that have
metric size wheels are stuck and often find it hard to get stock and if
they do manage to find some they are paying over the odds for them. The
only alternative is to change the rims to standard size rims.
A lot of people have followed manufacturers advice and
changed from something like 230/55/390 to 225/55/16. If you're looking
for Metric size tyres, please give our call centre a call on 0845 094 09