Originally Posted by fastnoypi
The max inflation on the sidewall is a safety max at cold tire pressure prior to bursting concerns that can be caused by bumps and road hazards once the tire air warms up.
Exceeding past the manufacturer's max load cold tire pressure recommendation will lead to a smaller contact patch with excessive wear in the center of your tire . It will affect handling characteristics and braking distance which is unsafe. You're compounding the risk of a blowout being in a heavy SUV.
Not worth the risk to the safety of yourself, passengers and others on the road, just to save on a few gallons of gas IMO.
Even if you doubled your fuel economy for the life of the car (lets say 10 years), which at 12,000 miles per year with a base fuel economy of 25 mpgs, you are saving about $1500 per year with an average gas price in the low $3s. Double the rate at which you have to replace tires because of excessive wear in the middle which we will assume will cost you $1000 every 2 years and the net amount saved is around $10,000.
So is $1,000 per year over 10 years worth a horribly bumpy ride and extreme safety risks to your family and friends? If you want to take risks go throw that $1,000 into the VIX - today you would have profited nicely!