Even after many practice trials it was still difficult to get all the cars to start and run well.
Some of the problems were wheels pushed together making too much friction,
string not the same lengthen, rubber bands braking, meter sticks not taped straight, or cars aimed straight.
We got most of the details worked out.
The math was not too hard - We added and divided by three.
The results supported our hypotheses of the small size drive wheel going the farthest.
Two trial out of three we could see the big wheel drive was the fastest. Big also went the shortest distance.

Final distances





Pictures of pieces.