Originally Posted by borfoo3

I've been running my LT KO2s for a while at 35 psi, and always felt like it was under-inflated.
So after inflating my tires yesterday I went through a quick calculation to see what number makes sense.

The goal is to see, given the same load per tire, at what LT tire pressure we get the same as stock P-rated tire pressure? Here's how it went:

Stock 4runner suggested tire pressure is 32psi

Bridgestone A/T Revo (P 265/70 r17)
load @ max pressure = 2535lbs @ 44psi


My tires: BFG KO2 (LT 275/70/r17)
load @ max pressure = 3195lbs @ 80psi


going by per tire load @32psi = (32/44)* 2535 = ~1844 lbs per tire (meaning at 32 psi the stock tires can each carry this load)

to get the same above per tire load on the LT: (1844/3195)*80 = ~46 psi

The above assumes a linear relationship between tire pressure and tire load capacity, which may not be 100% true.

However, this tells us that the LT tire needs ~46psi to provide the same load rating per tire as the P-rated stock tire. Again, not 100% accurate, but to me seems like a good start point.

Ride will suffer (LT tires are stiffer) but may helps some mpgs. Plus they finally 'look' right!