I'm going to guess your Tradesman came with 245/70/17 tires? Just like my '12 that is a ST (same as a '13 Tradesman) and all other trims that have 17' wheels come with 265/70/17 wrapped around them. That would be roughly a 150rpm difference, and the difference you see with RPM's compared to some others. All '13 SWR are 3.42's.
When I installed my 35" tires from my 245's, I went from 1800rpm @ 70mph to 1650rpm. This is with an auto tranny and a manual will be slightly higher rpm's.
When I installed my 35" tires from my 245's, I went from 1800rpm @ 70mph to 1650rpm. This is with an auto tranny and a manual will be slightly higher rpm's.