Looking at your profile pic I think those look like KO2's. I'm on my 2nd set of KO2's on my '99 FJ 100 LandCrusier. Used KO's before that and before that the plain old TA/AT all totaling around 340,000 mi.
36 psi on the road. 20psi for washboard and it flies like the wind. I get 15 mpg on the highway and 11 mpg 'round town. And I completely agree with
@9Mike2 regarding the drive to the Racetrack in DV. I've had the FJ100 out there a couple of times and other long washboard road out there (e.g. Saline, Eureka Dunes). 20psi works great for me.
I'll air up to 40 - 60 if I'm towing something with a heavy tongue weight or I'm really loaded down depends on the weight.
It's a good question! I'm still getting the feel for my tires on my 4Runner. It came with brand new Goodyears so it's tough to just change 'em out. I miss my BFGs....