I just burned up about 4 hours of my life trying to sort the facts from the fiction in
this thread and other related sites and threads concerning putting more than the placard recommended tire pressure (NOT SIDEWALL MAX) in your tires.
The gist of what I got is this
1. tires are safe to sidewall pressure. But past 44 psi your valve stem might leak pressure.
2. a tire pressurized to max sidewall will likely last longer and not deteriorate at all compared to a tire at OEM recommended pressure for your car (usually 32 psi) but people who sell tires would rather you don't know that.
3. tire mfg companies are in bed with petroleum companies because they both rely on the same raw material. So why would a tire company give you a cheap and easy way to cut into their profits as well as the profits of their partners in the petroleum industry?
4. If I inflate my 50 psi max inflation tires to 50 psi, I should expect a bit more slipping under low traction situations (snow, ice, dirt, rain). But if I'm hypermiling, I wouldn't be pushing that envelope anyway, would I?
5. radial tires will NOT wear out in the middle more than the sides due to inflation to max sidewall psi. Tires on the rear of rear wheel drive vehicles will do this, but due to it being rear wheel drive, not inflation pressure. Front wheel drive tires will likely wear evenly on the front, while the rear tires will harldy wear at all. This also comes from personal experience as a recovering lead foot with many a mile behind me.
6. Don't buy cheap, Korean, or Chinese tires. They have higher failure rates.
The ONE official article I found (and can't find again) indicated that a radial tire will not blow up until it gets to 150 psi, and even then it would require high speed antics to finish the job. So a 50 psi tire set to 50 psi is as safe as you can get. a 44 psi tire to 50 psi is still likely very safe. a 32 psi tire to 50? Meh, you should spend more money on tires mate!
There is much discussion concerning how race car tires deteriorate in these threads. PLEASE, for the love of all things holy, RACE CAR TIRES ARE NOTHING LIKE PASSENGER VEHICLE TIRES!!!!!!!!!!! They use different rubber, different tread (or lack thereof) and are designed with different life expectancies. So there is no comparison. If you drive a car like it's a race car, expect your treadlife to diminish. But having your pressure at sidewall max isn't going to change much. If anything, underinflation is the anti christ, while max sidewall psi is an innocent baby.
While I don't have any technical data to back up these claims, reading as much as I have concerning tires and applying logic to the missing bits, I believe this rant is as balanced a viewpoint as I've seen yet. Put your tires to max sidewall, drive like you want to squeeze every last foot from each drop of petrol, and you'll be fine. But endless debate is only going to confuse the uninitiated. So if you have something to say contrary to this bit of common sense, prepare to prove it immediately!!!!