The loadindex system research
I have been studying the loadindex system and found out next.
Already clear is that it is originally made for KG wich is international standard, and conversed to LBS.
For every 24 LI steps higher the Lmax gets 2 times more, and the the other way around , for every 24LI steps lower the Lmax gets half of it
Example LI 108 Lmax 1000KG/2205 LBS
So 108-24=84 LI Lmax 500kg/1102LBS
And 108+24=132 Lmax 2000kg/4409LBS
But you can compare this with every LI step of 24.
I calculated this back to 1 step and came to times 1.029302 for every LI-step higher. For on the road use thats 3% higher for every Li step so in the LI/speedstep-sysem here given 10km/6.3m/h lower speed .but in spreadsheets we can calculate as accurate as possible.
This system is somewhat distorded because the steps are grooped in logical steps like 25 kg /20kg/15kg to prevent that it gives for instance 802kg as Lmax. So sometimes it gives 3 li steps more for 20 km/12.5m/h lower.
So instead of comparing with Li steps for speed you can also say that for every 10 km lower the L max gets times 1.029302 more. But 2 steps gives squaire 1.029302=1.059463 and so on.
So you cant say that for 24 steps it would give 24 times 3 % more maxload = 72% more , we already came to the conclusion that its 2 times as much so 100% more. It the same as combined interest on you loan.
This would mean that if you compare a J Vr tire to a N Vr tire thats means 4 times 10 km lower speed means 1.029302 to the power 4 = 1.122462 times Lmax so 12.25 % more maximum load then the N speedrated tire because of the lower speed Lmax is calculated for.
This strokes with what I once calculate for ST that it had about 15% higher maximum load then an LT tire. Only compared one tire for wich I did not notice the speedcode of LT, so probably Q speedrated LT.
So the loadindex-step /speed-step system I first gave can be refined by this combined multiplication factor system.
In my spreadsheets I will implement this system to give more realistic damage and bumping border.
But this means that you have to give yet another extra input , think I will pre fill the fields with same speeds and optionally you can chanche it.
Here a list I made with Excel use it like this. If J speedrated and you want to compare with N , look behind N and see 1.122462 , then divide given Lmax by 1.122462 to get the Lmax for if it was calculated for N speedrated.
K 1,029302
L 1,059463
M 1,090508
N 1,122462
P 1,155353
Q 1,189207
R 1,224054
