So I’m switching from the 16” Westlakes to 17.5” Coopers… So the question is do I inflate to max pressure on the tire (which I did with the Westlakes) or do I look at the tire/pressure load chart and set the pressure based on axle loading per the CAT scales. I used to set the pressure on my Airstream based on the chart but haven’t had a chart till now. Chart attached
Always off the the load/inflation chart when a chart is available from the tire manufacturer.
Our Coopers on two rigs were both calling for 125 psi. I’m based in a warm climate and inflated them to 120-122 or so cold, in the shade. Never had an issue on either rig. When we went to a colder area the TPMS showed them down to 108-110 cold, in hot climate traveling they will get up to 130-135…
We have the Coopers and the sidewall is 125 however based on scale loads plus 15% safety margin the chart calls for 85psi (14122/4=3530). That’s the number I’m going to inflate to. Should handle the load easily and provide a softer ride.
I’m replacing our Goodyear G114 tires since they’re a little over 5 years old with Sailun S637 215/75R 17.5 next month.
Trailer weighs just under 17K (16740) and when hooked up the axles are 12340. Pin weight is about 4400 too.
I think I’m going to split the difference between the weights (14540) and use 95 PSI.
First off that will work but according to the chart you’re still over inflating. If you take the 14540/4=3635. According to the chart that calls for 75psi… I would probably split the difference between 75 and 95 and go with 85psi. FWIW
Makes sense. I’m going to get updated weights before I decide on the pressures. The ones I posted are a bit out of date. I think I’m probably a bit heavier now too.