I don’t even run 80 psi on my diesel at almost 19,000 lbs combined with my 35ft RV….

That 80 number is the max rating for every load range E I’ve ever seen. You could get scientific, weigh axles and refer to a load chart(a bit pointless, I’ve done it since I have access to my dads semi scale.)

How inflated they look, and how they feel driving are the main things.

At 80 I’ll bet the 4runner is an oversteer king on the gravel! Mine is a ton of fun at 40 for oversteer on the gravel curves.

I know if you do the conversion from an SL tire to LTE you end up at 44psi or something for the max GCVWR on a 3rd gen if I remember right.

If you’re not towing, 36 to 40 is going to be money and will let you do interstate speeds. If you’re doing a town putt around and never go above 65, you could undercut that. LTE tires suck driving around under 36 psi on pave. It makes it to where he almost literally cannot do interstate speed under 36 psi.