I've got the 295/70 Toyo MT's with an auto and 3.73's, love the way they look and fill the wheel well but am really considering downgrading to 285/70 and maybe AT for my next set. Did pretty good towing only about 6.5k (flat front bumper pull lots of wind resistance) about 4000 miles but there were many times I'd wished for better gearing to keep the Cummins in the sweet spot and not exceed the speed limit to much (especially CA with their 55mph limit for any auto pulling a trailer).

 

I just got back from pulling the trailer 800 miles. Took it up for a wedding. We went over I-84 over the Blues, up Cabbage Hill, etc, freeway driving, two lane etc.

I can't compare before to after but I think the muffler helped, I didn't feel like I had the same power issues up the hill, just kept the rpms up a bit higher, cruised on the freeway about 65 most of the way, kept the rpms just under 2K so I think I'll keep the tires, most of the hills where fine, Cabbage hill, I think that it's, out of Pendleton headed south, was a pull but you can only go 45 up it and I moved along fine. Muffler sounded fine during normal driving, you could hear it as I stepped on it.

I do think that 285's w/o mods is about as big as a person wants to go. Any bigger and your going to loose power without some adders. Next on my list is a Smarty and that should help with the mileage. I got about 9 hand calculated best I figure.

-Josh