I am thinking about getting larger tires if I can get them through the Michelin warranty. I currently own a 28' travel trailer but I don't want to mess anything up for the future (possible 5th wheel or 38' TT). My upsize options would be BFGoodrich A/T TO size 285 or the 305. I am worried about the difference in load rating D vs E even though they are rated at the same weight. Also I am worried about messing up the gear ratio and towing capacity. I have a 2006 2500 CTD MegaCab with the full towing package. Should I be worried? They are not much larger, nothing like the 35" tires I see on some of the forum posts. Thanks for your help.

 

Most posters are more interested in the macho factor of larger tires than economy. In general, the stock size allows your engine to perform at the most economical RPM.

Load range E is a tougher, heavier tire than D. I had a D tire throw a tred (with camper loaded), and now with E tires of the same capacity and many more miles I have not had a problem.

 

You should have no problem running 285's.

I ran 285's on my 01 and really could not tell any noticable pros or cons performance/towing wise... they did look better though!

 

Go to this website & plug in the stock tire size and the size you wan to change to. The bigger tire will have lower rotations per mile. Figure the percentage difference between the two. Then multiply that percentage by your axle ratio. The result is the "effective" ratio you wil lend up with.

http://www.csgnetwork.com/tireinfo4calc.html

Example, say the stock tire rpm is 1000 and the new tire size is 800. The percentage will be 80%. If you have a 3.73 ratio, your effective ratio will be 2.98. These numbers are purely hypothetical.