Originally Posted By: Char Baby
How much PSI, Up or Down can we run in our tires without hurting their structure? For example, I like a bit more PSI in the front and either, even or less PSI in the rear.
In other words, if my door jamb label says...F:30/R:30 but for ride comfort I like...F:32/R:29, is this OK?
Or, any combination of there or about!
Another example is, I have a vehicle that states on the door jamb label...F:32/R:32 but, I like, F:30/R:28...Is this OK as well?
I think you should use the placard pressures as stated. If you are unhappy with that, then change the tires to something you do like.
But at the very least, I would not use less than what is stated on the placard. And I wouldn't recommend going higher than 5 psi over the placard
Please note: All this assumes you are using the same size as listed on the vehicle tire placard.
Originally Posted By: mattwithcats
.........Remember the Ford Explorer?
Dealers were told to put a new door sticker on, original had recommended pressure too low, tires failed, vehicle rolled....
Sorry, but the inflation pressure was not what caused the tires to fail. I know this doesn't support my argument above, but here's my take on the whole Ford/Firestone issue:
Barry's Tire Tech - The Ford / Firestone Controversy
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And lastly. I am NOT a fan of using the chalk test. Not only does it assume that the tread profile is optimal at the optimal pressure (not a really good assumption), but there are so many variables that it would take many readings under many different conditions to get a good basis. Besides, the tread profile of radial tires is relatively insenstive to changes in pressure - as shown here: