What's the formula to calculate the maximum tire width allowed by a certain wheel width? Does anyone know?
For example, a lot of people quote 275 mm as the maximum width of a tire for a 9" wheel. But nobody bats an eye at the 94-95 Cobras, which mounted a 255 mm tire on an 8" wheel, which is actually more extreme.
275 mm tire :: 9" (228.6 mm) wheel = 83.1% wheel/tire ratio, 46.4 mm difference
255 mm tire :: 8" (203.2 mm) wheel = 79.7% wheel/tire ratio, 51.8 mm difference
And then there's the 93-95 Lightnings, which mounted a 275 mm tire on an 8" wheel, or a 73.9% ratio and a whopping 71.8 mm difference.
I did some searching through the forums and even Google, but I didn't find any convincing answers anywhere. I was trying to figure out if I could put 295 mm tires on my new rear wheels for my 95, which are 18x9.5" with 6.12" backspacing.
They have 265 mm tires on there right now, which amounts to a 91.1% ratio and a 23.7 mm difference. Slapping on 295s would change that to a 81.8% ratio and a 53.7 mm difference.
For reference, new Lightnings mount P295s on a 9.5" wide tire - but I didn't know for sure if that applied to a Mustang. The largest wheel/tire difference I could find in a Mustang were the 1993 Cobras, which mounted 245s on a 7.5" wheel = 77.8% ratio, 54.5 mm difference, but that's also a 17" wheel, and I don't know if the increased sidewall height allows for a larger difference or not.
Any insight would be appreciated.
For example, a lot of people quote 275 mm as the maximum width of a tire for a 9" wheel. But nobody bats an eye at the 94-95 Cobras, which mounted a 255 mm tire on an 8" wheel, which is actually more extreme.
275 mm tire :: 9" (228.6 mm) wheel = 83.1% wheel/tire ratio, 46.4 mm difference
255 mm tire :: 8" (203.2 mm) wheel = 79.7% wheel/tire ratio, 51.8 mm difference
And then there's the 93-95 Lightnings, which mounted a 275 mm tire on an 8" wheel, or a 73.9% ratio and a whopping 71.8 mm difference.
I did some searching through the forums and even Google, but I didn't find any convincing answers anywhere. I was trying to figure out if I could put 295 mm tires on my new rear wheels for my 95, which are 18x9.5" with 6.12" backspacing.
They have 265 mm tires on there right now, which amounts to a 91.1% ratio and a 23.7 mm difference. Slapping on 295s would change that to a 81.8% ratio and a 53.7 mm difference.
For reference, new Lightnings mount P295s on a 9.5" wide tire - but I didn't know for sure if that applied to a Mustang. The largest wheel/tire difference I could find in a Mustang were the 1993 Cobras, which mounted 245s on a 7.5" wheel = 77.8% ratio, 54.5 mm difference, but that's also a 17" wheel, and I don't know if the increased sidewall height allows for a larger difference or not.
Any insight would be appreciated.
