Because we are only conversing to higher speed it can even be simpler.
So converse every tire you find and want to compare first to 160km/99m/h.
J =100km/62m/h| -6 LI-steps|-15.0%
ST=104km/65m/h| -6 Li-steps|-15.0%
K =110km/69m/h| -5 LI-steps|-12.5%
L =120km/75m/h| -4 LI-steps|-10,0%
M =130km/81m/h| -3 LI-steps| -7.5%
N =140km/87m/h| -2 LI-steps| -5.0%
P =150km/93m/h| -1 LI-step | -2.5%
Q =160km/99m/h and higher up to V no reduction.
Then now what maximum load do you need for that 160 km/99m/h.
Law is that your tires must bare at least the GAWR ( gross axle weight rating) so for 2 tires on one axle half of that and 4 on the axle 1/4th of that.
This would mean that an ST tire to law can support a higher GAWR.
But to laws of nature its better to go from the conversed to 160km/99m/h maximum load and the tires together must bare at least 110% of the GAWR.
If you ever weigh per wheel(pair) then you are sertain of the weights, and might prove that my reserve of 10% is absolutely needed to cover unequall loading R/L.
Mind also that if you have Dual load ( 4 tires on one axle) that the maximum load is 7.5% less or 2 LI steps (5%??) lower in European system, and American system even often uses 9% lower or 4LI steps lower ( 10%??) .
This strange difference between percentage and LI-steps is because of rounding down from the calculated maximum load to the first lower LI step. And the difference between EUR and USA is a matter of different opinion about what is needed for it in the system.
so if you want to be on the save side substract for every tire 9% fromm single maximum load, regardless of what is printed on the sidewall.
