[sbrumund]

In simple physics terms friction is independant of the surface area.

In reality because we are on a textured surface it may not be.

If the wheels are the same as last years kit wheels the surface is a soft compound. With sufficient weight on each wheel the soft compound will conform the the bumpy surface producing more friction than a wheel riding on the top of the bumps.

The question then is what is then optimal load on a wheel to obtain the most friction. A simple experiment can be designed to determine the optimal loading and therefor the optimal number of wheels.

If allowed the vacuume design is possible. Many schools physics departments have a 4' diameter hovercraft where the lift is achieved with a battery powered leaf blower. The leaf blowers run well for 10 minutes on a charge and can easily support a 250 lb load. I believe the battery supplied has sufficient energy to power the leaf blower and drive motors and increase the normal force and friction. You would need a fully charged battery for each match.

Since we are simulating 1/6 gravity on the moon and there is no atmosphere on the moon I suspect a vacuume design wil not be allowed.

It is possible to get used to driving on a low friction surface. Those who are used to driving on ice and snow understand the limitations. Keep in mind that when driving a car on ice you are in the car and have a, seat of your pants, feeing of what is going. You do not have this sensor input at a remote driving station.

It is possible and easy through programming to limit how fast you can accelerate and turn. It takes some time to get used to, like the first time you slam on the brakes of a car with anti lock brakes.