What size are the tires? What width are the rims? How much weight are you carrying?
The best way is the chalk test. Chalk the treads of the tire. Drive straight on level ground for a little bit. Check your chalk marks. If the chalk is gone on the edges tire pressure is too low. If the chalk is gone in the center tire pressure is too high. (Disclaimer: never done it myself ) But it sounds like that would work well.
If you fill them up that much you will have a harsh ride. I've never heard of anyone running over 50psi in an FJ6X
Tires are 33 X 9.5 X 16 and I'm in an 87 FJ60. It is usually only lightly loaded and sometimes heavily loaded for bush trips. I would sacrifice some ride comfort for MPGs. I drive about 300 miles a week.
Yes you can put 65PSI in them, but I wouldn't unless you have 3000lbs of wiegt on each of them. If you run them w/65 psi w/o 3k lbs on each of them, it will ride like a rock. And you won't be putting all the tread to the pavement. My rig weighs in at almost 5k lbs and I have found 35 psi to be a good pressure.
Actually they are load range D with 5 ply tread (1 nylon, 2 steel, 2 poly) and 2 ply poly sidewalls.... Cooper discoverer S/T and they are actually a bit over 33 at 255/85, 16 . I know about your BFG woes.... And cruisers seem to have them so often. I bought a few cruisers over the years with all-terrains and it was just blow out city. To put it simply, I hate those tires. Anyway, gonna try 40 psi and see how she goes. Thanks guys...
That used to be true, but now weight rating is assigned based on test results, so ply counts can vary. With aramid and other wovens, there are a number of ways to vary strength based on the warp and weft count and how the plys are offset, so E range tires can be 5 ply.
Yes, I'm a textile nerd. 20 years in the industry.