Most likely 85, but you need to read the side walls of the tires themselves to see For sure.
85 is what my E rated tires on my fifth wheel are.
Most ST or LT type LR-E tires call for 80 psi cold inflation. What size do you have?
I write a blog on RV tire application and safety. RVTireSafety.com
Also give seminars on tires at RV events across the US. 40 years experience as tire design & quality engineer for major tire mfg. Freelander 23QB on Chevy chassis is my RV