Will 315/75 R 16 tires work or will I need spacers?

 

With or without a lift? With new wheels or stock wheels? That is a 35" tire and it will rub without a lift and without wheels with less back spacing.

 

sorry its with a TF 2.5 BB

Also would that tire be better with a 16x7 with 4.0 backspace or 16x8 with 5.0 backspace? Whats the difference?

 

Definately go for the 16x8. That tire is basically 35x12.50-16. 7" is too narrow in my opinion, given the option.

 

The difference is one inch of backspacing.

The 16x7 with 4" of BS has 4" of BS

The 16x8 with 5" of BS has 5" of BS

Changing the width of the rim doesn't change the backspacing, or the clearance inboard that the backspacing provides....as backspacing IS the distance from the most inboard side of the rim, to the hub face.



A 315/75/16 is about like a 35x12.5/16 tire....and, for 12.5" section width tires, most people need about 1.5" of BS less than stock...stock rims have 6.25" of bs, so, 4.75" of BS is probably the MOST BS you would want.

IE: If you HAVE to pick EITHER the above 16 x 7, with 4" of BS, OR the 16 x 8 with 5" of BS, ONLY the 16 x7 of the two has less than or equal to the 4.75" of BS most people like for a 12.5" Section Width tire, like your 315/75/16.

Hope that helps a bit.

(BTW - its OFFSET that changes when the rim width changes, not BS)



As for rim width vs tire width - offroad, HUGE numbers of people run 12.5" tires on 7" rims, and have zero problems. (I have an Xterra that's run about 120K so far with 7" rims, 80K of which are on 12.5" section width tires...the same set has lasted 80k, so far.



Generally, for street use, the handling is better with the wider rim...but, if you think about it...an 8" rim only sticks out 1/2" more on either side....not a giant leap either way.

Of course, if you find a 16 x 8 rim with 4.75" of BS or less, you could use that too, etc.