Hi, I was going to buy 30x11.5x16" Interco Thornbirds for my truck. It has no lift, the 30's should fit since that size tire was an option offered on my truck. The only problem I have is what size backspacing I need on the rims. I did some crazyass equation and came up with 3.5" wich seemed reasonable to me. I know that some Mickey Thompson Classic II's come with 3.75" backspacing, so I thought I could use those. So how much backspacing would I need, or is it something I need to find out by doing my own measurements?

 

Do you have a 4x4 or 4x2? I don't think a 30x11.50-16 was ever an option as that is a very odd size. Most 4x4's came with 265/70-17's which is basically a 32x10.50-17 tire. Whether you have a 4x2 or 4x4, a 30x11.50 should fit, but I'd try to stay close to the OEM wheel's backspacing (4x5 inches) if you have a 4x2. Also, I would recommend you go with another tire. The SS Thornbird has to be one of the worst tires ever made.

 

its a 4x2, i was on tirerack.com and they said the 255/70R16 was and option for my truck and i guess it translates to 30x11.5x16? If not the thornbird, which tire should I get? im one of those all in one place shoppers, where if one major site doesnt have it, it doesnt exist unless i know prior to it. I'm still playin around with like 3 or 4 ideas and havent decided yet. if i dont lift the truck it will give me more money for cosmetics. I mite body lift it and put on 33s and leave it until i can buy a truck with less mileage.

 

A 255/70-16 is basically a 30x10.00-16 tire. Since you have a 4x2, I'd suggest going with a 265/75-16 (32x10.50) tire on a 16x8 inch wheel with 4.5 inches of backspacing. This is a very common size and will fit at stock height, but will also look good with a 3 inch body lift.

 

ok, thanks for the help