Originally Posted by DavidNERODease

I have used full synthetic motor oil to lube all belts since the HPI Micro RS4 days. A racer discovered that the lubrication greatly increased speed due to reducing the belt friction from rubbing on the chassis. But when I tried it I noticed that the pulleys NEVER EVER get clogged with junk when racing on carpet which was also a major problem on the car with our surface. Since then I've lubed every single touring car belt and have not needed to clean a pulley in well over a decade. Never had any issues with the belt skipping even at low tensions. Never had to replace a belt due to wear either.