Here was a recent post about tire inflation on an RV forum. This statement is sometimes correct but not always:
Always run any trailer tire to maximum inflation tire pressure cold! Period! Never run underinflated!
I offered this reply:
In my opinion, a broad-brush statement like this can be misleading as it is not correct 100% of the time.
Certification Labels
Federal law requires that all RVs come with “Certification Labels” that include VIN, GAWR, tire type, size and load range. It also must include the minimum inflation needed for the listed tires to support the stated GAWR (Gross or maximum Axle Weight Rating), plus some non-tire related information.
Most RV trailers come with tires that meet the minimum requirements for the GAWR when the tire is inflated to the highest level for that Load Range. However, there are a few RV companies that provide tires that can support more than GAWR if inflated to a higher level of psi than required to just support the GAWR as a minimum.
Car and light truck tires
Almost all passenger cars, and some light trucks, come with tires and inflation numbers that have the tires exceed (some by 20% to 40%) what would be considered GAWR. Cars do not publish a GAWR because they are not expected to be loaded to the physical maximum of the car suspension.
I can point to one example of a car company that compromised vehicle load capacity in favor of ride comfort. This decision eventually caught up with them, when hundreds of tires failed due to overloading and underinflation.
The Car Inflation number is selected by car engineers to deliver tires and inflation that meet a shopping list of performance features including fuel economy, noise (more than a dozen specific sounds), handling (another dozen specific maneuvers), traction (wet and dry), along with additional features.
Proper tire inflation is not Rocket Science
Yes, the proper inflation level takes a little thought and understanding of tire nomenclature and performance requirements. However, it’s not Rocket Science—even though many folks treat the question of tire inflation as if it were Nuclear Science.
We have many posts on proper tire inflation here on RVtravel.com. I also have numerous posts on how to select inflation for your RV, both motorhome and trailers, on my blog.
NOTE: I have used many tire-related terms in this and other posts. Please be sure you understand the meaning of each of these terms. There are many posts on various RV forums where people use or misuse the terminology associated with tires and tire performance. Sometimes they clearly do not have a solid or correct understanding of the terms they are using.
Please review this and other tire posts I have made, and confirm you understand the meaning of the tire vocabulary you are using. Speaking or writing about tires almost requires a different language.
Roger Marble
*****
If you have tire questions, check out Roger’s Blog as well as his posts on RVtravel.com. There are hundreds of posts covering everything to do with tires.
If you still have a question for Roger after searching the above posts, send your inquiries to him using the form below.
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Thank you, Roger for all of your help here to protect us from the “Armchair Einstein’s” that seem to believe THEY know more than the engineers and the millions of dollars spent on R&D, on a multitude of RV issues, especially tires.
iRV2 has a bunch of these.
Thank you, Roger! 🙂 Have a great week, safe travels, amd safe stays! 🙂
Thanks again Roger for sharing your knowledge!!
Please note that a lot of RV Travel readers actually read and follow your advice.