Thursday, September 21, 2023


RV tire safety 101: Old news for some, but important for new RVers

With over 300 posts here on and with almost 600 on my blog, I sometimes feel like a broken record. But when I see the same or similar questions raised almost every week on various RV Forums, I have to conclude that there are still many new owners who have not found the answers to the questions they have about RV tires.

So please bear with me if you already know the information I am posting today, and just consider it a refresher course.

1. How much air do you need in your RV tires? Most important, we need to protect against overloading our tires. With most RVs on the road having at least one tire or an axle in overload, this is a most basic need. For many years RVs have come with a Certification Label mandated by Federal Safety Regulations. The labels may look like these:

2. The labels have the VIN for the RV and the GAWR (Gross Axle Weight Rating), which is the Maximum you should ever have loaded on the axle. The label also has Tire Size and Load Range (aka Ply Rating), as well as the inflation needed by the tires to carry the load. On a Class A, the label is located near the driver’s left elbow. If you have a driver door in the motorhome, the labels are on the driver door jamb. If you have a trailer or 5th wheel, the labels are on the outside, driver side toward the front. While helping an RV owner a couple of weeks ago we discovered that the information on his label had been polished right off the sticker so he will need to contact his RV manufacturer to obtain new labels. I suggest that every RV owner capture a picture and keep copies in a couple of locations.

3. Inflation needs of the tire are determined by the load you place on the tires. Every RV should at least once stop at a truck stop scale and learn the actual load placed on their tires. In tests, it has been shown that essentially no one can look at or “kick” their tires and learn the correct inflation. If you want the facts, you need to get on a truck scale. Here is a video showing the BASICS. The more experienced folks will note that the trailer in this case only got the total for both axles, which is OK for learning the basics. There are other posts here that cover the advantages of “4-corner weights” but I want you to at least get the basics. Here is my latest weight sheet.

4. If you want to confirm your MINIMUM inflation required, you can just confirm your actual axle weights are lower than the GAWR numbers on your Certification label, or you can consult a Load Inflation table like this.

5. I have a number of posts on how to use the tables, but as long as your weights are lower than the Certification Label GAWR you can use the inflation numbers on that label.

6. You should check and set your inflation when tires are at Ambient temperature, i.e., temperature in the shade. This means before the tire has been driven on or in direct sunlight for the prior two hours.

7. You should have and use a tire pressure monitoring system (TPMS) to warn of air loss due to cuts or punctures. There are a number of posts here at under the Maintenance section on testing and programming your TPMS and how to care for your tires.

Roger Marble

Check out my Blog www.RVTireSafety.Net

Read more from Roger Marble on


Roger Marble
Roger Marble
Retired Tire Design and Forensic Engineer w/50+ years of experience. Currently has Class-C RV. Previous Truck Camper, Winny Brave, Class-C & 23'TT. Also towed race car w/ 23' open trailer and in 26' Closed trailer. While racing he set lap records at 6 different tracks racing from Lime Rock CT to Riverside CA and Daytona to Mosport Canada. Gives RV and Genealogy Seminars for FMCA across the USA. Taught vehicle handling to local Police Depts


  1. Thank you, Roger! We get four-corner weighed at every opportunity. We also are not full-timers, so we vary what we carry every time we travel hoping this prevents our rig from ever being overweight. (Some storage bays are actually empty.) Our TPMS is built into the chassis software and uses bands inside the tires, around the wheel. We bought additional bands and had them installed on our towed vehicle. Those pressures and temperatures also are displayed on the dash of our DP. Thank you for writing for RV Travel and thereby keeping a whole lot of travelers safer.

  2. Very good article! it should be paired with articles on “how to find the age of your tires” and “when to replace your RV tires”


Please enter your comment!
Please enter your name here

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Sign up for the

RVtravel Newsletter

Sign up and receive 3 FREE RV Checklists: Set-Up, Take-Down and Packing List.