We were running 110 psi on our tires and had each tire weighted and based on the tire chart ran our tires at 95psi for a year. We got some real bad wear on the outside and inside edges of all four tires. The following was pointed out to me and I have gone back to 110 and it has solved our wear problem.
"Unless trying to resolve poor ride quality problems with an RV trailer, it is recommended that trailer tires be inflated to the pressure indicated on the sidewall of the tire. Trailer tires experience significant lateral (side-to-side) loads due to vehicle sway from uneven roads or passing vehicles. Using the inflation pressure engraved on the sidewall will provide optimum load carrying capacity and minimize heat build-up.
Under: Weighing Your RV
http://www.goodyearrvtires.com/tire-selector.aspx"