Tire Pressure Question

[OldCoot]

Originally Posted by MuddauberE

...It does matter if you change tire ratings and even size as mentioned by OldCoot and Pap. recommended tire pressure is based on factory tires for your vehicle. So if you did upgrde, then your door jam is probably wrong. But even with factory tires, look at the door jam, and then look at the MAX PSI. they are not the same. Usually about 20 lbs off. Your max air pressure is just a safety rating. go above that and your being dangerous. Always check with the dealer if there is a question and they will tell you the same thing. Always get more than one "opinion".

If you change tires to a different LR, the factory door sticker means nothing. Tow Vehicle mfgrs are not interested in anything but the "Ride" of the vehicle, not tire wear or performance when loaded. On the trailer, I inflate to max sidewall pressure in the morning and go with it. If it happens to be colder and the pressure is less than I set it for the morning before, I air them up. If it is warmer and the pressure is above the max, I lower the pressure to max. I never adjust pressure during the day while towing. The tires are built to withstand the temperature/pressure change while running. The TST TPMS has warnings you can set to alert you to a % increase in pressure and an alert on the temperature that you can set.

[pappcam]

Originally Posted by MuddauberE

If you always put the recommended tires on your TV as recommended from the dealer, use the door jam. The TV was designed to ride safely and smoothly at a specific tire pressure whether it was towing or not. Even with tires marked as max PSI, it is not recommended to fill to max. Always stick to the door jam and or sticker for recommended PSI on both the trailer and TV. I learned this from more than one dealer. Max PSI is just that "MAX".

Imaging if you filled a tire to max PSI. then the next day, you drove to your campsite. the site was a couple hours away and the weather was hotter that day. Air expands. now your "MAX" pressure is above max and you have a great chance of having a blow out and causing improper tread wear.

It does matter if you change tire ratings and even size as mentioned by OldCoot and Pap. recommended tire pressure is based on factory tires for your vehicle. So if you did upgrde, then your door jam is probably wrong. But even with factory tires, look at the door jam, and then look at the MAX PSI. they are not the same. Usually about 20 lbs off. Your max air pressure is just a safety rating. go above that and your being dangerous. Always check with the dealer if there is a question and they will tell you the same thing. Always get more than one "opinion".

Max. pressure ratings are always based on "cold" pressure which basically means the tires are basically at standing temperature meaning they have cooled off from any previous driving. The ratings take into account rising pressure from the tire heating up in use. I guess if you were cruising through Death Valley at 120 degrees you may have to take outside temperature into account. I believe my door jamb indicated 1 35psi rating on my original P rated tires. I still pumped them up to about 42 when I towed as it greatly lessened the squishy sidewall flex issue. I now have E rated tires so I go by the manufacturer ratings and not the door jamb.

[elind]

GM has 75# front/ 80#rear on my door post and the tires are 80# max..

[TURBS]

Originally Posted by elind

GM has 75# front/ 80#rear on my door post and the tires are 80# max..

My 08 says 60f 80r

TURBS
08 duramax tuned n modded, 32bhok Sabre
2015 camping "2 nights"

[elind]

Originally Posted by TURBS

My 08 says 60f 80r

TURBS
08 duramax tuned n modded, 32bhok Sabre
2015 camping "2 nights"

When ONSTAR detects air pressure in the 60s I get a reminder that 75/80 is needed.

[Witch Doctor]

My truck tires were Pirelli came from Ford. They where aired to the door jam. Bought new tires Michelin, same size and same ply 10. The dealer aired them up to what the door jam said. Now my trailer came with "C" rated at 50 lbs sticker said that was the pressure to inflate cold. I went to Marathon "d" rated ST. the dealer inflated them to 65lbs. My rims could also hold that pressure stamped on the inside. I run them at 65 lbs as he told me to....