WD40 is safe for plastics, but it is more messy than using a something like graphite powder.

entirely way too messy..

is running without any lubricant or powder ok? thats what im doing right now.

Re: vaseline good for gears?
 

I used to use Vaseline on my 1/10 and 1/12th scale cars. It's cheap, and works reasonably well. It does attract dirt, though, so regular teardowns and cleanings are required. It works fine for the gears if used sparingly. (Don't just gob it on) For the bearings, I use a lightweight oil.

#2 pencil + nail file = graphite for gear happiness and no trip to hobby shop required. (the formula used by many happy pinewood derbys)

#2 pencil and nail file? sound good to me, but where exactly should i sprinkle this powdered graphite

It's actually good for any parts that need to connect and move together including the gears, axels, etc.

Just be careful to clean any other lube that may already be there first. If you mix the graphite with other lube it will make a mess and reduce efficiency, thus negating the point of the graphite.

ok then, thanks everyone.

could you use yo-yo lubricant? ive got tons of that:confused:

Isn't that yoyo lube just wax?

use cooking oil it would work perfectly

dont use cooking oil. i used olive oil when i first got the car, not even alot, i used a toothpick, and after like 5 mins of run time the entire car was slimey and greasy and its a pain to get off. stick to dry lubes if at all possible.