Friction is enemy number one when racing pinewood cars. Your car gains speed when rolling down the track’s slope, and then friction steals that speed on the flat portion of the track. Cars that rub against the track or have wheels that rub a lot on the car body don’t win. Some don’t even finish the race.
You can reduce friction by making sure the wheels don’t rub too much against the car body and the car axles. The easiest way to do this is by lubricating the car’s wheels. Lubrication makes the wheels slip around the axles, reducing friction. Have you ever noticed that the gym floor at your school is slippery when it’s wet or when your shoes are wet? The water is acting as a lubricant and reducing friction between your shoe and the floor.
Of course, you don’t want to use water to lubricate your car. Most of it would drip off and the rest would dry out before the race was over. Water wouldn’t be allowed on your car anyway — lots of races have rules that you must use dry lubricant. Hobby shops and locksmiths sell little tubes of powdered graphite that you can put on your car. Some places have powdered teflon, too. Both work really well. Be careful with these, they’re very messy. Make sure that your lubricant only goes on your car, and work outside if you can.
Lubricate your car a few days before the race and then spin the wheels a lot. This will help work the lubrication into the plastic. Some of it will stay there long after the race is over. Don’t just lube the inside of the wheels. Make sure you get lube between the wheel and the car body and between the wheel and the nail or screw head too. Anywhere the wheel will rub against something it should be lubricated.
The day of the race, lube your car again at the last possible minute. For most people, that means you do it at the race, just before you register your car. Don’t touch the wheels after that. You’ve already worked as much lube into the wood and plastic as you can, if you spin the wheels now, you’ll just be knocking the lube off.