Mythbusters test golf ball-like dimpling effect on fuel economy

[Matthijs]

http://green.autoblog.com/2009/10/22/video-mythbusters-test-golf-ball-like-dimpling-effect-on-fuel-e/

It works? I remember reading on the forum that it did not increase fuel economy.

[NeilBlanchard]

Hi Matt,

The difference is (I think) that this time the dimples are fairly large in size, whereas the previous reference was the "skin" that had pretty small dimples. Or, Mythbusters made a mistake somewhere in their testing.

[KarenRei]

And it's obviously also going to depend on the geometry of the vehicle in question.

[danieloneil01]

I would hate to wax a car like that.

[OC-LA driver]

I've seen some cars in Colorado look like that after a hailstorm :fighting0027:

[speculawyer]

I've seen some cars in Colorado look like that after a hailstorm :fighting0027:
Not a bug . . . a feature!

[jstdadd]

... Or, Mythbusters made a mistake somewhere in their testing...

What? Mythbusters make a mistake in testing? Give 5 people who are 'special effects technicians' a TV show and then we expect them to follow rigorous scientific testing methods?

GUFFAW!:jumping0004:

[byplug]

The XL drive Aptera 2e:

http://www.byplug.com/aptera_xl_long_drive.jpg

[jstdadd]

Try it with 'inverse dimples'!

[byplug]

XL drive Aptera 2e with 'outies'...

http://www.byplug.com/aptera_xl_long_drive2.jpg

[roflwaffle]

Did they account for weather? If they went from even a ~2mph headwind to a ~2mph tailwind at 65mph, that would cause the change in mileage seen.

[overpowered]

They tried to make it as fair as possible but indeed, it was not a well controlled test.

They really should have done it in a wind tunnel and measured the drag. It should also be done by aerodynamics experts.

I do think that their results suggest that it merits more study.

[randyd]

I do think that their results suggest that it merits more study. Certainly for box-like cars that drag a large wake around at 65 mph. For the 2e, I am sure the dimpling would only hurt, not help.

[jimgolian]

It is well known that the dimples on a golf ball reduces drag, which causes the golf ball to travel further. Can this be applied to the shell of a car?

I was watching Mythbusters on the Discovery channel and they tested this myth. They tested a small scale dimpled car in a wind and water tunnel. Sure enough, the small scale dimpled car had reduced drag. They then decide to test full scale. They put dimples on a real car to see if it would reduce drag and increase energy efficiency. The car actually had a 10% improvement in gas mileage!!!

So if Aptera truly wants to reduce their drag coefficient further, they must put dimples on the Aptera!!!

[Sapphire Dragon]

Lol! While an interesting thought, putting dimples on a car may not be the best option. A car doesn't just sell for reduced drag- it sells for design as well. And dimples on a car... might not be the most attractive thing. Not to mention, that would require more complicated construction than a smooth surface and thus cause increased costs. Maybe, if they want to make an Aptera 0d (0 drag) then they could consider dimples. But I'm not sure if they would consider that, even then.

[KarenRei]

So if Aptera truly wants to reduce their drag coefficient further, they must put dimples on the Aptera!!!

Actually, that only works on vehicles that aren't already super-streamlined. On a vehicle like the 2e (at least, the way it was initially), you're not really dragging a wake. So no need to waste energy causing turbulence.

[10.5]

The Corbin Sparrow had/has dimples:
upload.wikimedia.org/wikipedia/commons/0/0c/CorbinSparrow..jpg

[randyd]

The Corbin Sparrow had/has dimples:
upload.wikimedia.org/wikipedia/commons/0/0c/CorbinSparrow..jpg

http://farm1.static.flickr.com/8/6495725_6c7c7c46af.jpg
From an aerodynamic point of view, the Sparrow looks a lot more like a golf ball than a 2e. The dimples might well reduce the size of the wake on a Sparrow for the same reasons it does on a golf ball. I don't know. But I would bet my reservation number that dimples on a 2e would not lower aerodynamic drag.