Mine also came with the Ranier 235/80R16F tires and I just got rid of them with less than 1000 miles on them. I bought Westlake G rated tires of the same size that are a 14 ply with much more substantial sidewall and bead. I looked up the Ranier tires on the internet and the replacement cost for them is $88.00. Frankly, I'm not going to trust my $50,000 coach to a set of $88 tires. I would recommend stepping up to a G rated tire. We just pulled our HC from Omaha to Rapid City over the last couple of days and the ride and handling of the drive was much better as well. The only change I have made has been the tires.
2018 High Country 321MK
2017 Silverado 2500HD Duramax Diesel