Tire Width Chart, How wide a tire to use

[xnickx]

With the help of information I came across on the internet, I compiled this chart that might be of some help to some.



These are safe measurements, for example I am running a 225 on my 9" wide rim, but it is highly recommended to stay within the chart if possible.

To be used as a guide only, always check with the guys selling the tires, as some manufactures will have different specs of what can be loaded onto what width wheel.

Highly stress, this is to be used as a guide only, I take no responsibility for any damages etc that you may occur whilst following this chart.

[4TEZNU]

Thanks for the info, just a question as I too am outside the parameters, I am running 215 on a 8.5" wide rim but the tyres have not been stretched on (well the don't look it) so whats the damage/problem running outside this table?

Thanks

[Nunga]

People really do go overboard when stressing any concerns about stretched tyres. A 215/45 on an 8.5" wheel will cause no trouble at all. Excessive stretch can put excessive strain on a tyre's sidewall, but you'd have to go a lot tighter than that. I had 215/45s on a 9" wheel, and 235/45s on a 10", never had trouble with the 5-0, never had trouble with wear. Grip might have deteriorated a bit but I wouldn't have noticed.

For what it's worth, on my IS200 I have 17x8.5s, running 215/45ZR17 Bridgestone Potenzas. I found Federal 595s didn't stretch as much despite being 215s as well, and that's another factor- tyre brand.

[Nunga]

To continue, many tyre shops won't fit tyres outside of the above parameters because the rolling diameter will be too far out from factory specs.

http://www.1010tires.com/tiresizecalculator.asp A good guide to see how much your speedo will change with various tyre sizes.

[2ToneTezza]

I ran 255/40 Goodyear F1s on my 17x8 rims without problems. I did measure the actual tread width at around 245mm though.
it would be interesting to see how much difference there is between stated and actual widths of different tyres/brands. I suspect it could vary quite a lot.

[nz_climber]

Remember that is a general rule of thumb, most tyre Manufactures have there own specs that they recommend for any given tyre. As it also depends on rim diameter and aspect ratio

For example Bridgestone and Toyo say 205/50/15 can be mounted on a rim 5.5-7.5inches, so outside of what the table says is safe.

As another example(bridgestone) that shows aspect ratio affects the fitment:
205/50/17 permitted widths 5.5-7.5
205/45/17 permitted widths 6.5-7.5
205/40/17 permitted widths 7-8

So look up what the manufacture say, and follow that.. they spend a lot of money on their research!

[CLM877]

I know it is not recommended but does that mean that it is illegal to go below/beyond the listed size above? (Esp in NZ)