I have a 2014 Big Country fifth wheel (35 ft,) I have Goodyear G614 (LT235-85R16) trailer tires on my rig and was told by Camping World to run them at the min of 80 psi (posted on the placard of the camper) We are parked next to another Big Country (41 ft) and he said he was told by a tire dealer who sold him the same kind of tires, to run them at a min of 110 psi and never go below 100 psi. My tires are also nitrogen filled. I was told to contact Goodyear Customer Service but was interested in other owners experiences.
Hi Jttiger2,
In general, you would want to inflate your tires to the Maximum Cold Inflation pressure stamped into the sidewall of the tire. For a GY G614, that's 110 psi.
More specifically, it sounds like your Big Country might have started out with tires that had a Max Cold Inflation of 80 psi, and that might have been enough to support the portion of the GVWR that sits on the tires.
So for example, if your Big Country has a GVWR of 14,000 lbs, you might have as much as 12,000 lbs sitting on the tires - and maybe even less. The rest of the GVWR is carried by the truck's hitch.
So let's say you have a theoretical 3,000 lbs on each tire. More likely, the weight in your rig isn't evenly distributed. So maybe you have 2,800 on one wheel and 3,200 on another.
You'll want some safety margin in the load capacity - so let's say you add 500 lbs (about 15%) to the 3,200. That would say you'd want 3,700 lbs of load capacity.
At Max Cold Inflation of 110 psi, the G614 has a load capacity of 3,750 lbs. At 100 psi, capacity is 3,550. At 80 psi, the capacity is 3,042.
If you over inflate tires relative to their load, you can get excess wear in the center. So you might want to back off a bit from 110 psi if your GVWR is in the 14,000 territory. Maybe run at 100 psi.
One important point. If your wheels originally came with 80 psi tires, you should check the inside surface of the wheel to see if it's rated for 110 psi/3,750 lbs. It would be dangerous to mix 110 psi tires with 80 psi wheels.