Tires: Tire sizes, dodge ram 2500, cummins diesel

Question
Hello
I have a 2004 Dodge Ram 2500 4X4 Quad cab with a 6 speed and cummins diesel. The original tires are LT 265/70R17 load range E. I have 80,000 plus miles on them and they still have some usable tread. I do very little off roading. My use for the truck is 99% expressway use and occasionaly hauling my harleys around the country. My question is I would like to go with a taller tire when I replace the original tires. I was told that would effectivily give me a taller final drive ratio and lower my rpms on the expressway. When I go 60 mph I can get 25-26 miles per gallon with the rpms at 1800-2000. As soon as I get up around 70-80 miles per hour 2500 rpms my milage dips into the very low 20's or lower. What is the largest recomended tire size for my use with stock 2500 rims.

Thank You,
Larry Counts

Answer
Larry,

According to Tire Guides, your Ram has 8" wide rims, so this is not going to be the limiting factor.  You can put up to a 315 wide tire on that rim.  BTW you want to stay with an "LT" for load capacity reasons.

Unfortunately I won't be able to tell you what fits under the fenders.  I just don't have a book that tells me this stuff.