I need new tires on a 2015 3500 DRW. I have a mix of Michelin LTX A/T fronts and Michelin Agilis on rear. Asking if the LTX are worth $400 more for a set of 6. With my factory wheels all i can do to rotate is side to side. The LTX'S have a 60,000 mile warranty but realistically there both going to be 35 - 40 thousand. TIA for any input