Cadillac Owners Forum banner

Tire pressure...FYI

14206 Views 14 Replies 8 Participants Last post by  LDYNREDD
I have a very accurate, professional grade tire gauge.....found that the cold pressure reading of my tires was 38psi....three over the rec. When I was rolling .... checked the pressures via the dic info page and they were up to 41!!!! So.....took the cold pressures down to 35 and now the "hot" rolling pressures are up to 37/38....much better road feel!
I did read somewhere that many vehicle manufacturers over inflate the tires prior to transport.....but the dealer should have checked that and taken the pressure down. The other important aspect of this is that these are "low profile tires" and they will "heat up" quickly and pressure will rise much faster than "normal ratio" tires! ....get a good gauge and check those pressure readings....better ride, better tire life!!
1 - 1 of 15 Posts
Higher pressure is never unsave for the tires.
The given maximum pressure written on sidewall is the maximum cold pressure the tire-maker alows.
this is not the pressure at wich the tire is allowed to bare its maximum load up to 160km/99m/h, wich is also given on sidewall as loadindex or maximum load.
This pressure I will call AT-pressure further. For P-tires ,AT-pressure is 35psi in American system ( EUR 36 psi) .
But most likely your low Hight/Width division tires are XL/reinforced/Extraload wich have AT-pressure of USA 41 psi, EUR 42 psi.
I once got hold of the official formula to calculate pressure for lower then maximum load.
So dont be afraid of the higher pressure .
I once read that tires are tested to stand an absolute pressure of 2 to 3 times the AT pressure .
So a P-tire will blow somewhere between70 psi and 105 psi. A XL// tire between 82 and 123 psi.
Tire pressure advice is all about load on tire in ratio to maximum load , and speed you maximaly drive.
A bit about alighnment ( camber angle).
For lower speed the tire is allowed higher maximum load for the same AT-pressure .
And vice versa higher speed lower maximum load.
See less See more
1 - 1 of 15 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.