Looking to adding a lift kit to a '09 Chevy Silverado in the near future. I was wanting to get people's feedback on Pro Comp's Xtreme A/T Tires. They look like a well made tire and a good alternative to BFG's A/T (the price of the BFG's have greatly increased in my area the past few months) My truck would be driven aprox. 85% on road/ 15% off road. Are you really getting near 40,000 miles off of them as the warranty claims? Any tread seperation problems?