Proper Tire Air Pressure

I'm learning how to pre-trip in school now and I've watched several videos on pre-tripping. When it comes to air pressure they all say "... inflate to manufacturer's specification on the tire" or something to that effect. My problem with that is when I was working as a mechanic, we were taught that the air pressure listed on the tire is the MAX pressure that tire can handle and the vehicle manufacturer's air pressure is located on a sticker in the frame of the driver door. It seems to me that this would also be the case with CMV's. I also did a forum search for "proper tire air pressure" and while I found several informative threads on this subject, none of them addressed this question. If anything, someone stated that their company has their own specification. Which one is it, door sticker (vehicle manufacturer), tire (tire manufacturer), or something else entirely (company specs)?

I'm learning how to pre-trip in school now and I've watched several videos on pre-tripping. When it comes to air pressure they all say "... inflate to manufacturer's specification on the tire" or something to that effect. My problem with that is when I was working as a mechanic, we were taught that the air pressure listed on the tire is the MAX pressure that tire can handle and the vehicle manufacturer's air pressure is located on a sticker in the frame of the driver door. It seems to me that this would also be the case with CMV's. I also did a forum search for "proper tire air pressure" and while I found several informative threads on this subject, none of them addressed this question. If anything, someone stated that their company has their own specification. Which one is it, door sticker (vehicle manufacturer), tire (tire manufacturer), or something else entirely (company specs)?

When in doubt, default to calling your company and asking them.

If I had to give you an answer, I'd say inflate to cab sticker pressure, provided that the pressure is lower than the tire's rated pressure.

On our pretrip exam, we had to state that the tire pressure was,100-110 psi or ma ufacturers rating. Of course the max pressure is listed on the tire.

Ok, so it's one of those situations where you say one thing to pass the test and then follow the company policy later. That does make sense and was kind of what I thought it would be. Thanks for the responses.

Its that way very much. In my state there is no 3rd party testing and DOT does all of it. My school got a list from the DOT of exactly what they wanted and verbatim on how it was to be said. You could add things but you couldnt leave anything out. That list was 10 pages long.

If you didnt say exactly what they wanted to hear, you failed. They're tough but they do give you 4 separate testing attempts for the initial fee. The examiner told me the average number of attempts to pass is 3.

Ok, so it's one of those situations where you say one thing to pass the test and then follow the company policy later. That does make sense and was kind of what I thought it would be. Thanks for the responses.

Sort of..100-110 is actually what I keep my tires at. 110 is what Swift likes them at.