[chali481]

I just bought 7.5 wide wheel for my 08 dually and I was asking myself what is the largest size of tire i can put without using spacer I haul 20 000 pounds almost everyday i was thinking to go on 275-70-17 ? or 285 but do I need spacer and is it safe to roll with 20 000 pounds with 2 inch spacer ?

 

[meteor56]

A 275 tire will be 21 cm wider than the stock 245. Loaded, with tire pressure at the max of 65psi (you did not say what dually you have, so I'm working off my 350), measure the space between the tires. You need at least 1 3/4" to keep 275s from touching. If you don't have that, you will need a spacer. A spacer may also lead to needing longer studs.

I don't know about safety of using spacers when hauling heavy. I personally would not use them. YMMV.