The size difference between the two sizes you mentioned of 235/80-16 and 235/85-16 are so close that going to the larger size is a great idea. They both fit the same wheel dimensions as well.
Check out the Westlake Tire part # LHWL410. This tire has a weight capacity of 4,400 lbs at 110 psi, a 75 mph speed rating and comes with a 2 year roadside assistance program.
If your RV or trailer has a flat tire, call the help line and a technician will come change the flat for you. You can call... view full answer...