Replaced all 4 in less than 2 years and 2000 miles @ 65 mpg.
They were OEM tires on my 5th wheel, blew 2 and found the other 2 had the steel belts crossed. - The tires are rated for 3500 lbs at 90 psi and max speed of 65 mph.
My RV is 13,500 lbs dry / empty, or 3300 lbs per wheel, add the 2500 lbs allowable cargo = 3800 lbs per wheel. Forest River sells the RV with tires running at or above the top end of their rated load capacity.
Most the comments about the Goodyear Marathon tires are negative.
I wouldn't recommend purchasing. If You already have them on your RV, replace them as soon as possible before they come apart and the repairs become even more expensive.