Do Most run it a little higher than what is on the door. (I run my Tundra at 40psi~ 44 max on sidewall) and after 50,000 wearing evenly and still plenty of tread
hard to say what most do. some. the good thing is, as you lose a little, you're still above recommended when you check them. unless you have a leak. i have never had the tpms light up.
It's going to cost you $50 dollars more for every 10k miles traveled with the Defenders with gas at $2 per gallon. Not a big difference considering the extra 35k miles you can get out of the Defenders. When I bought my Defenders, I lived in California and gas was $4 a gallon, so it would have cost me an extra $100 for every 10K traveled. That would have paid for a new set of tires every 60K miles. As long as gas remains low I wouldn't sweat the lower mileage, and the way things are going, gas may even get cheaper.