Tony Posted November 4, 2014 Report Share Posted November 4, 2014 On some tyres the actual width displayed is telling fibs? I appreciate that there are other factors contributing to the actual tread width once on the car and even more so once the car is in motion so maybe this is why some race series only allow one make of tyre? Key to reading tyre measurements Actual widths Avon ZZR 185/55/13 170mm tread widthToyo R888 185/60/13 178mm tread widthToyo R888 205/60/13 198mm tread widthKumho V70a 215/50/13 203mm tread widthToyo R888 225/45/13 221mm tread widthFederal FZ-201 195/50/15 209mm tread widthFederal RS-R 195/50/15 176mm tread widthToyo R1R 195/50/15 183mm tread widthToyo R888 195/50/15 191mm tread widthKumho V70a 195/50/15 180mm tread widthKumho V70a 195/55/15 190mm tread widthFederal RS-R 205/50/15 182mm tread widthYokohama AD08r 205/50/15 196mm tread widthToyo R888 205/50/15 198mm tread widthKumho V70a 205/50/15 208mm tread widthYokohama A048 205/50/15 208mm tread widthToyo R888 225/45(&50)/15 221mm tread widthKumho V70a 225/50/15 206mm tread widthDunlop DZ03G 225/45/16 230mm tread widthDunlop DZ03G 225/50/16 235mm tread width Quote Link to comment Share on other sites More sharing options...
chrisgixer Posted December 19, 2014 Report Share Posted December 19, 2014 Often wondered how the stated width relates to the actual contact patch on the road? Given variances in profile/pressure/vehichle weight I guess there's almost no accurate correlation at all? Eg....Given my 18's will take a 235 and a 245. This doesn't necessarily mean a 245 will have a wider footprint. Just points to the differance in that particular manufacturers sizes, relative to the next smaller or bigger size. Quote Link to comment Share on other sites More sharing options...
Tony Posted December 19, 2014 Author Report Share Posted December 19, 2014 An extra 10mm width will only give about a true 2mm in the actual contact patch. Width does however gain lateral grip regardless of the contact patch so there is a subliminal gain. Quote Link to comment Share on other sites More sharing options...
parthiban Posted December 19, 2014 Report Share Posted December 19, 2014 I still don't quite understand that, a tyre with a certain profile has a particular contact patch. If you had the exact same tyre with the exact same profile but now an inch wider, surely it's exactly the same contact patch longitudinally but wider by an inch? Quote Link to comment Share on other sites More sharing options...
chrisgixer Posted December 19, 2014 Report Share Posted December 19, 2014 Possibly. But a list of width sizes, as given with differant makes and models that clearly give differant widths, doesn't mean those makes and models will give a footprint directly relative to the width measurement. Assuming the same make and model would give best chance, with a wider size. Fluid dynamics and pressures aside. To my thinking anyway. ...? Interested to see what Tony and others says reguarding this. Quote Link to comment Share on other sites More sharing options...
Tony Posted December 20, 2014 Author Report Share Posted December 20, 2014 This shows how width changes the size and shape of the contact patch.... Quote Link to comment Share on other sites More sharing options...
anothercarguy Posted July 5, 2022 Report Share Posted July 5, 2022 Sorry to revive this thread but where did you find those actual tyre widths? I'm currently looking to upgrade my 205 tyres to 215 but if my current 205s are more like 208 fitted and the new set of 215 that I want is more like 210 then I'll be paying a lot more for a more awkward size for not a lot of benefit. Thanks Quote Link to comment Share on other sites More sharing options...
Rich Posted July 9, 2022 Report Share Posted July 9, 2022 On 05/07/2022 at 13:25, anothercarguy said: Sorry to revive this thread but where did you find those actual tyre widths? I'm currently looking to upgrade my 205 tyres to 215 but if my current 205s are more like 208 fitted and the new set of 215 that I want is more like 210 then I'll be paying a lot more for a more awkward size for not a lot of benefit. Thanks Sadly Tony is no longer with us and I have no idea where he got those figures from. I guess it's going to depend on what brand tyres you have fitted now and what you're planning on replacing them with. I must've missed this thread when Tony posted it but it's not something I've ever thought about. Quote Link to comment Share on other sites More sharing options...
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