Track the growth of your Hot Wheels kids with a racer's take on a DIY growth chart. It looks totally amazing but is so simple to make. Learn how to make one yourself with step-by-step instructions here.
The Science Behind Making the Fastest Possible Pinewood Derby Car
You wouldn't think that a four-wheeled car would go faster if one of its wheels didn't touch the ground. Or if its axles were bent. Or if it was designed to grind against a wall. But you'd be wrong, and here's the science to prove it.