I have a 2003 Dodge RAM 2500 with the Cummins and I think I've settled on Goodyear Wrangler SilentArmor. The truck, apparently, takes LT265/70R17 but it seems to come in two service ratings. 112R and 121R. What's odd is that the higher rating (more load capacity?) tires, the 121R, seem to be about $20 a tire cheaper. Am I missing something or is the 121R choice best? It also seems to run under a much higher preassure.

 

I dont know the numbers, but higher pressure usually means greater load capacity. I work at American Tire/Discount Tire off and on, but I work in the garage, so all I know is the higher capacity=heavier=poorer fuel economy=unhappy. I have load range E tires and I wish I had gotten D b/c of the weight. Hope this helps

 

Eric, yes the 121R should be load range "E" tires and capable of holding 80psi. This is what our trucks came with from the factory, and is what we should be using.

 

Hmm. I bought the truck used with Firestone Destination A/T P265/70R17 113S on them. I wonder what difference I will see in ride, handling and mileage if I go back to an LT E rated tire.

 

I am currently those tires with an E rating. They are very nice. If your hauling get the E, if it's just a ride to work the D/C rating will be fine.