What is the Proper Tire Pressure

By Jack Bradshaw - Reprinted from Winter 2004 Motorcader

Bobbie and I have been traveling a lot this year on motor­cades and attending events. One question that is always asked is, "What is the proper tire pressure that I should use?" Well, I hope the following information will answer that question for you.

The importance of proper tire pressure

The most important factor in maximizing the life of your tires is maintaining proper inflation. Driving on a tire that does not have the correct inflation pressure for the load of the vehicle is dangerous and may cause premature wear, tire damage, and/or loss of control of the vehicle.

A tire that is under-inflated will build up excessive heat that may go beyond the prescribed limits of endurance of the rubber and the radial cords. This could result in sudden tire failure. An under-inflated tire will also cause poor vehicle handling, rapid and/or irregular tire wear, and an increase in rolling resistance, which results in a decrease in your fuel economy. Don't need that these days with the price of fuel.

Over-inflation will reduce the tire's footprint or contact patch with the road, thus reducing the traction, braking capacity, and handling of the vehicle. A tire that is over­inflated for the load that it is carrying will also contribute to a harsh ride, uneven tire wear, and will be more susceptible to impact damage.

How much air pressure should I carry in my tires

Federal law requires that the tire's maximum load rating be molded into the sidewall of the tire. If you look on your tire's sidewall, you'll see the maximum load allowed for the size tire and load rating, and the minimum cold air inflation pressure needed to carry that stated maximum load. Utilizing less air pressure means a lesser load can be carried by the tire.

To determine the proper tire pressure for your coach you must know the actual vehicle's fully loaded weight. There are a couple of ways to do this. One is to go by a truck stop scale; Flying J usually has one. The best way is to go to an FMCA or Foretravel event that RV Weight Safety (A'Weigh We Go) is attending. They put a scale under each wheel, which reads all four-load points at the same time. This will give you a better understanding on where the load may need to be adjusted. A load chart is provided on the sidewall by the driver's seat that gives the coach weight information.

Just remember the weight changes after you start loading all the things needed to make traveling so enjoyable. After you know your vehicle's actual loaded weight, look in your own­ers manual at the tire inflation chart to determine the correct tire pressure. So, motorcaders, get your coach weighed, get the proper tire inflation, get on the road, and enjoy your coach while traveling safe.

Overloading or Under inflating your Tires

© Barry Brideau 2003-2018