The fact that most(if not all)of the studies seem to be on the dangers of low pressure says a lot; to me anyway. I suppose that there could be a higher risk of catastrophic failure at higher psi but, in the 25K+ with the Prius and the 10's of thousands of miles on my other cars before it without a failure, seems to suggest that the risk is either very minimal or that I'm one of the luckiest guys on the planet. Since I've never won the Lotto or a sweepstakes I'm leaning away from the latter. I have even run at freeway speeds for over 550 miles at a stretch in 90F temps without incident. rpg51, as for negative treadwear results on your tires, I'm not familiar with those softer compounds but I will say that I have never seen a tire's tread life shortened yet due to increased psi.
Well, sure, underinflated tires will certainly fail; but who deliberately runs underinflated tires for any distance? The only reasons to underinflate that come to mind are 1. better traction when stuck in sand 2. trying to gain a couple inches to get under a low bridge. So, heck yeah, pump those babies up to 60 PSI. Woo-hoo! :_>
Gungadin and Diamond Larry have it right, this was discussed adnauseum about two months ago. One fellow ran his tires at 70lbs and got 70mpg! I did experiment at various stages of 50,60 and 70 and could see little difference in mileage. The ride was a little rougher at low speeds but actually smoother at high speeds going over pot holes. I have since returned the pressures to 55lbs. I have a depth guage and find that the center tread is always more than the edges. Which is strange. I think it was DiamondLarry that 70 at 70. I say never run the tires at the pressures on the door frame, unless you like to buy tires.
GUNGADIN & JOHN1701a - thanks for your input. as i stated before, i DO run 42/40. gungadin - would you say that if i ran 42/40 COLD PSI, it's safe to take a 1,400 mile trip with these psi's?
When I first got my 05 I traveled from Sacramento to Florida and back at sidewall pressure (bead pressure) 42lbs on all 4, No problems at all.
If an Integrity failed under those conditions either it was defective or it got punctured. All tire ratings include allowance for heating during use. In September I drove 2400 miles through west Texas and New Mexico with 42/40.
At those psi pressure on the low 40's it should not be a problem. I opt for 40 Fr and 38 Rr then did an 800 mile ride to Cape Cop. Mpg was still in the low 50's. I love them Integrities.
Last summer we did a 7,500 mile coast to coast trip-- two adults, two teens, and all the camping gear. 48/46 and all is well. Since then I've kept them at 50/48. The tires are about at their end now. Still some tread in the middle, but getting smooth on the outside edges. PA P
