Originally Posted by JohnD10
Because THAT is what most people with RV trailers use to pressure their trailer tires to!
None of us weigh each tire every time we roll so that we can faniggle our trailer tire pressure to be exact for the daily drive.
Heck, if we did that we wouldn't be able to even eat a sandwich out of our loaded food without re-weighing and resetting air in our tires.
Or we wouldn't be able to run the fridge on propane as, with your theory, we'd have to reweigh and reset our pressure every 25 miles!
OK, then again I don't understand why it is so difficult to read the vehicle certification label aka Tire placard sticker where for almost every trailer I have looked at you will find the inflation pressure that is associated with the max pressure for that Load range tire.
LR-C = 50
LR-D = 65
The sticker is on the outside driver side toward the front of the RV. the print is a standard size and if you can't read the sticker you should not be driving due to poor eyesight.
IF you get into a situation of changing tire size or Load Range then you need to educate yourself a bit and need to understand what you are doing. IF you make that change there is nothing preventing you from using a label maker and sticking the tire size and proper minimum cold inflation number info next to the original sticker. I wouldn't cover the sticker.
Yes to lower the interply shear you need to run the pressure associated with the max load. You also need to confirm with actual scale measurements that you have AT least 15% load capacity margin on the heaviest end of each axle.
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. 40 years experience as tire design engineer. Freelander 23QB on Chevy chassis is my RV. Giving seminars on RV Tire applications (not selling)@ FMCA Conventions. Next in Mar 2021 in Perry, GA