Trailer Tire Question

JIMNLIN wrote:

Dealer recommended replacement tire same size Good Year Endurance load range E made in USA max load 2830 @ 80 psi. He said it was absolutely ok to run the new tire at 50 psi along with the remaining 3 original tires. I have been a little uneasy about the underinflation of this tire.

You should well feel uneasy.
This speaks volumes about this dealers experience with tires on trailers. Lawn service trailers don't count.
A dealer with experience in the trailer field would know better than to make a rookie recommendation such as running a 80 psi tire at 50 psi. There is nothing gained by derating the E tire to 50 psi according to this tire engineer . Read his blog on http://www.rvtiresafety.net/2013/10/will-you-increase-load-capacity-with.html. Spend some time on his blog.....lots to learn from a actual tire engineer.

Your 7500 lb loaded trailer doesn't tell us your OEM tire size and load range or your trailers axle ratings.

A 7500 lb trailer = approx 1875 lb per tire. Now add a good 10-20 percent reserve = around 2200-2300 lbs per tire.

Your math is correct and your margins for reserve are good. Using Goodyear's tire inflation chart and the tire size on the OP's trailer, he should inflate his tires to 50!!!!!

I will go with what Goodyear says rather than what someone posted on the internet!!!!!