Mate I've had 3 D40s, 2 X 2.5 litre fours and 1 V9X V6 turbo diesel, I've always run them at 40 PSI all round and running BFGoodrich All terrain TAs and Micheline I average 140,000 before I need new tyres, always rotate every 10,000 klm front to back and back to front, keep an eye on balance and...