quote:Dimples or surface roughness could reduce pressure drag if there's enough flow separation, but they can also increase drag due to surface friction. So it would depend on body style, but I'm guessing that most modern car designs would not benefit from a rough body surface. Maybe vans and hatchbacks could benefit from some dimples right before the rear hatch? I'm also guessing that waxing would not make a measurable difference in fuel economy. I'm waiting for the wind-tunnel results before I'll believe it.
Originally posted by Shannow: I think it's the other way 'round. A golf ball has dimples to affect the boundary layer (http://en.wikipedia.org/wiki/Golf_balls), and provide less drag.
quote:Tell your coworker to wax his car in better ventilation, I think the fumes are getting to him. The difference would be sooooo small at normal speeds that it couldn't be reliably measured.
Originally posted by Jonny Z: A coworker of mine claims that he gets better MPGs after waxing the car. While this is reasonable it seems to me that the difference is most likely too little to tell. Anyone?
quote:yeah, and catch all the bugs and cops' radar.....sounds likely truckerlore to me. If wax helps, it's certainly not measureable by the means available to the car driver, and if he "can feel it", he's dreaming.
Originally posted by blupupher: I had heard this also, but it was in reference to semi trucks. The truck with the freshest wax job (sometimes paid for by the other truckers) would get at the front of a convoy to break up the air.