What's the minimum gap between the front suspension arm and the sidewall?

[Scott]

I'm looking at wider tires. I've noticed that for the same tire width, say 255, the published section widths for different tire mfg, vary a few tenths of an inch, even when measured on the same width rim.

TireRack says that spec is difficult to measure accurately and so there may be some error in the data.

What's the practical minimum gap between the front suspension arm and the sidewall? If it is less than some fraction of an inch, should I run the 3 mm spacers offered by billybones?

I know many folks have the attitude that if it doesn't rub after a test drive, then its okay. Maybe it is.

I want to be a bit conservative. I don't really know what safety margin or conditions that the engineers had in mind when they provided that small gap with the 225 tires.

I realize that a bent rim or wider tires are two conditions allowed for. For example, aren't some RTs equipped with 235's from the factory?

Are there any dynamic conditions, hard cornering, blow-out, or whatever that might distort the tire and rub hard on the suspension arm?

Am I being a worry-wart??

[formerice]

I've got the no longer made BFG's in 255/55/18. About 3/16" space. I guess the 245/55/18 have a bit more, but theres a back order for those. I know many guys are going with the Toyo Proxes. I have heard a few guys liking the General, light truck tires in 255/55/18 so that might be a safe bet.

[GasGunR]

If it misses, it misses... the clearance shouldn't ever change regardless of manuver, as long as nothing breaks.