Confused...?)

O.K., now I'm confused regarding tire psi. Every post (most every) ends up recommending that the coach be weighed, preferably all four corners and then, based on the mfg.'s psi chart, air up to the chart psi for the weight carried. Makes sense! And, although I could only weigh the front and rear axles, I followed those instructions and based on the Goodyear chart and based on my actual weights, aired my 240/70R/19.6 H to 80 psi.

Now to the crux, steering has become a pain. Constantly adjusting the steering wheel to try to keep it going straight. This is a new development. Prior to having new tires put on and new Monroe shocks installed a few months ago, steering was not a problem. The tires being replaced were F rated and ( found out after the fact) the dealer installed H rated tires. Now, in my uneducated (psi) mind, I thought the new H tires might be the cause of the problem.

I called the RV repair shop I do business with and the mechanic advised to first have the front end checked for alignment. I did that this morning at a highly respected alignment, brake, tire shop. This is where the confusion takes place. The mechanic and the shop owner checked the tire pressure and said that my tires are under inflated. They pointed out on the sidewall the psi of 110 psi and said I should be running that amount or no less that 5 to 10 psi less. At running 80 psi, according to them, the sidewalls were allowed to flex too much contributing to the steering problem.

I tried to explain the reason I aired to 80 by weighing and using the Goodyear chart and, to my surprise, they didn't seem to know what I was talking about. So, I dropped the subject and told them to air up to their recommended 100 psi knowing that I could change it later if I wanted to.

They then did the alignment check and it did need some adjustment.

Driving home, steering was markedly better. Not perfect, but better and livable.

This alignment shop has been in business locally for over 50 years and has a superb record for quality service so I don't want to just discount their advice.

What they said about the tires sidewalls being allowed to flex more with lower psi makes sense. But, the Goodyear chart recommends that lower psi. Confused...yes.

Does the shop mechanic and owner have a valid point? Or, do I stay with the lower chart number?

Sorry about the wordy length.

Larry