Just wondering if anyone tows a decent sized load with 285's and if the tranny has any difficulty shifting into 5th.

Hi, I also have 285's on my truck thier bfg's. I have only towed my 5er once and that was only a short distance about 130miles or so, it seem to shift in and out a little but only on the bigger hills but it seemed normal. On the flat it went into 5th ok and stayed thier. I'll tell more this weekend going a little farther 350 400 miles.

The most I've towed is a little over 5,000 lbs, and that was with about 600-700 lbs in the back of the truck. All shifts were good.

I towed a 14.3K lb 5er with 285's, but only once. I sold the 285's and went back to 265's. Towed like sh*t with the 285's. Constant shifting out of 5th, even 4th...used way more fuel with the 285's also.

the only thing I found is that my mpg's went way down, I got 11 mpg on one tank and 11 on another. that seems a little low compared to what other trucks are getting pulling. so I may go back to 265 also.

I cannot comment on the shifting as I have a ZF-6. Are you manually calculating your mileage or did you have your PCM updated with the new tire information. This will skew your DIC results if that is where you are getting the MPG. I have 33's and averaged 13's with 50ft trailer and 3 cars aboard and my PCM was updated with my tire size.

i have a 15000lb fifth and i have noticed it pulls way better with the stock 245's then the 265's i have now. so tire size does change the performance. i will be taking it to the dealer so they can reprogram the computer for the 265's. hopefully this will make the 265's better.

I have 285's and this weekend I pulled the rig to the property. between my trailer and the ATVs I was pulling about 9000lbs. There are three big hills on my route all three are 6%m or more.

I had zero issues with shifting and got 11MPG. I did notice a difference when I changed from the 245s but the truck looks so much better that you could not pay me to go back. because I to so often I have toyed with the idea of trying 265s next time just to see the difference.