Originally Posted by BobW

I just use digital calipers. I would say accuracy would be +/- .1mm if you are very careful with the measurements. Give the same car to two different people and you will definitely end up with slightly different models.

What I always do when I finish a model is do a side by side visual comparison between the real thing and the graphic image displayed in the chassis manager. Placing the chassis on setup wheels or a stand helps with this. Notice any differences and check your numbers.

The important thing to remember is we are looking for the relative effect a specific change will have whether it's a gear ratio change or a shock spring. Does that change move the performance in the direction I want and what is the magnitude of the change big or small.