Here is my $.02. I have owned my 93 since 95, and it has pushing 200,000 miles and about 1/3 of those miles have been on 33X12.5X16.5 BFGMT load range D. I pull my 32' gooseneck that wieghs almost 7000 lbs, and put on at least one 6000 lbs truck on the trailer. With 3:55 gears, 5 spd, and the pump tweaked I have good luck pulling down the interstated in overdrive. When I put 2 6000 lbs trucks on the trailer or a 15,000 lbs backhoe my truck works VERY HARD. I don't know the exact size the original ones were but I think I will go back to some 32" tall tires and maybe only 10" wide, prolly some Michilen XPS Tractions with load range E 10 ply rating.
I noticed a milage drop from the stock tires which were about 31-32 inches tall to the 33X12.5. Yes the engins should turn slower but it has to push more air now. Empty on the street I could see no performace difference but for heavy towing you will notice. But I tow alot more than most people that haul their 4X4's on a small car trailer. There is alot of wind resistance with a big tractor up in the air too.
Email me if you want more info about you cummins, I love mine and will help you with yours!
I noticed a milage drop from the stock tires which were about 31-32 inches tall to the 33X12.5. Yes the engins should turn slower but it has to push more air now. Empty on the street I could see no performace difference but for heavy towing you will notice. But I tow alot more than most people that haul their 4X4's on a small car trailer. There is alot of wind resistance with a big tractor up in the air too.
Email me if you want more info about you cummins, I love mine and will help you with yours!
