RV Tire Pressure

There is a lot of discussion in the RV forums about motorhome handling. Of course, there all sorts of add-on accessories that range from expensive to very expensive and all sort of theories.  I have a very difficult time sorting the good theories from the bad.  Here’s what I know, Shaneeda is not new (twenty years old) and she drove pretty well but was more work and a much harsher ride than I wanted.

When I purchased new tires, the tire shop aired them as they normally do – maximum load pressure.  I didn’t know any better.

After spending lots of time reading, I now understand that RV tire pressure should be set based on weight.  There is no guessing here – you gotta have your motorhome weighed.

I discovered that the local co-op had a scale so off I went.  Turns out that Shaneeda has 5,000 pounds on the front axle and 10,500 pound on the rear with a fairly normal, going on a trip load.

As you know, I purchased cheap tires (a mistake) and they do not provide a weight chart. So, I used one of the commonly available charts. This isn’t ideal but I include a pretty fair safety margin so I think I am ok.

The tire charts show that, for these weights, 70 psi in all tires is plenty of pressure.  Hmmm, says I, that is a lot different than 110 psi.

A little subtlety that not everyone picks up on. If you have duals in the back then you have four tires carrying the weight.  In my case, each tire is carrying approximately 2625 pounds (10,500 pounds divided by four) so a pressure below 65 psi is enough.

So, I started decreasing the pressure each time I took a trip.  I REALLY noticed a difference when I dropped to 85 psi.  When I reduced to 78 psi, I became very, very happy.  Shaneeda rides so nicely!  The harshness is gone, every little crack and seam is not transmitted up your spine and into the center of your brain.  She tracks very nicely no longer requiring constant steering adjustments . Even in a cross wind she is pretty well behaved.

So, I am trying to spread the word!  Set your tire pressures according to the weight of your motorhome and see what happens.  I’m sure there will be some that still need some of the suspension accessories but maybe you’ll get lucky, like me, and save yourself some cash!