I currently have BA xr8 Rims on my xr6 (18x8) and will be due for tires soon. They currently have toyo proxes4s on them (245x35x18). And even with these tires on to some degree make the tires look too skinny for the rim so i thinking about putting 255 35 18 on instead to make the tires look more fuller and fatter on the rim. Just wanted to know what people think. So far i have compiled a list of tire sizes that i could use:

Ok so my Ba xr6 came calibrated with 17x8 size wheels which lets say = speedo dead accurate at 100km/h (Even though we know ford calibrated to -3% under if you all follow)

235 45 17 = 0% SPOPT ON
245 35 18 = - 2.3% at 100
245 40 18 = +1.5% " "
255 35 18 = -1.2% " "
255 40 18 = +2.8% " "
265 35 18 = -0.1% " "
235 35 19 = +0.6%
245 35 19 = +1.7%
255 30 19 = -1.2%
265 30 19 = -0.3%

Hope you all follow what im on about but basically i just want fatter tires and want to know if a 255 35 18 tire is too fat for a 18x8 or can i get away with a 265 35 18 as there is more to choose from

Cheers

The prob with trying that, is the low profile of the sidewalls......I don't know how it will go....trial fit maybe???

235's and 245's are common fitments to 8" wide rims. Different tyres can look quite different though, maybe your current ones are on the narrow side of the ledger. Have you looked at other cars, do you think they are too narrow as well? That's the first crucial point to establish i think.

A 255 or 265 tyre will offer more comfort and rim protection against scuffing, but less cornering stability.