# Community Forum

## Speed Formula

Forum Overview >> Farming Simulator 15

 Category Farming Simulator 15 Created 17.06.2015 00:06

Sheldon Major (Chaos_Darkrai) 17.06.2015 00:08
Hey, me again. I'm just wondering what the formula would be to calculate the speed of a mod, because I know the values of max forward/reverse, and min forward/reverse are used, and maybe the torque ratios, but I'd like a little more clarification on how to properly use those values.

Emil Drefers (Unknown) 17.06.2015 07:28
Hi,

to which values are you refering?

minForwardGearRatio / maxForwardGearRatio
minBackwardGearRatio / maxBackwardGearRatio

The maximum speed is calculated like:
v = maxRpm * math.pi / (30 * minRatio);

http://ls-mods.de/scriptDocumentation.php

If you want to set up the max. speed of a vehicle you can use a console command to reload changes to the xml file (not all of them):

So if you have changed something your xml file just use the above mentioned command or re buy the vehicle ;)

Cheers,
Emil

Sheldon Major (Chaos_Darkrai) 17.06.2015 15:24
Yes, those were the values I was referring to, thanks! I was just wondering about that, how I would calculate the speed.

*edit* When I calculate that formula, it doesn't match up to what is in-game... I noticed the maxForwardGearRatio and maxBackwardGearRatio is always 130, so how would I properly calculate the minForwardGearRatio and minBackwardGearRatio to the proper values? Say I want my tractor to go 40KM/H, just an example, how would I calculate the minForwardGearRatio?

Emil Drefers (Unknown) 18.06.2015 07:47
Hi,

the formula does match the ingame values.

Let's take the Deutz Agrotron 7250, which has a top speed of 62 km/h as an example and fill in the values for the formula:
v = maxRpm * math.pi / (30 * minRatio);

v = 2200 * 3.14159 / (30 * 13.5) = 17.065 (unit of this is m/s)
=*3.6= > v = 61.436 km/h

So, for the maximum speed you have to take the min. ratios into consideration.

I guess you can reformulate the formula to be able to calculate a ratio based on the requested speed.

Cheers,
Emil

Sheldon Major (Chaos_Darkrai) 18.06.2015 19:44
Thanks Emil, this has helped me out. I can see that the values only go up in increments of 0.5, and I used a little substituting in that formula, and a little trial and error to get the correct speed. This information has been super helpful, but so have you, so thanks Emil.

Richard Z (aaa372296237) 24.03.2022 04:28
How to modify the calculation formula of the speed? Where is the file for editing the calculation formula?

Richard Z (aaa372296237) 24.03.2022 04:43