I was told by a friend that you should always use the listed tire inflation amounts listed on the pillar and never go over. I usually have my tires around 3-4 lbs below the max inflation listed on the tire. What is correct? What are the drawbacks to tires inflated more than what is listed on the pillar, which I think is 30 psi for the fronts and 35 psi for the rears? Whay are the fronts and rears different?