What is the largest tire i can go with on my dually without running spacers in the rear?

 

On the 2012 we have put 26570r17 on them it gives you about 1/2 inch between tires at 70 psi.

 

I have a 2010...using 245 70r19.5 no spacers.

 

255/80/17 should fit with no spacers, but tire options are limited.

 

I run the BFG KM2 on mine. no issues. Only thing I did was level the front but didn't need to do that either and do not have issues in rear with tire spacing

 

Plenty of space between the dual with these plus 3000LBS in the bed full of gravel many times .I run the KM'2 on mine(255-80-R17)----coming up on 48,000miles of mostly hi-way driving with proper tire rotation,50PSI in the rear/55PSI front.I will buy again just for the fact that you do not need a spacer(I have Fred's spacer's sitting here unused just in case i want to step it up to Toyo's M/T 315/70/17 later on)I was just at Costco today kicking prices for the KM2's---up here in Canada things are a bit more $$$$ than USA-----best price so far is 279.00 a tire plus tax+15 to mount/balance.I will get another 5-7000 miles---so probable fall 2014 before i replace-----PS--- up here they are on back order until further notice.Cheers-DW