Not sure why, I pumped my tyres last week on my good old stockies at 35 on all 4 wheels, after 1 week all the wheels deflat pretty dramatically, lost 6 psi on each wheel and the rear left even more 20!!! I do normal road driving but do infact turn corners quite hard and fast.. does this effect it? if so does it effect it that much that it looses 6 psi in 1 week?? thanks all..