[nudephil (OP)]

Darren asked this question:

Golf balls are dimpled to disrupt the air flow around the ball. As far as I can gather this reduces the drag and allows them to fly further than they would if they were perfectly round. Why do we not see dimpled cars, aircraft or trains? If this effect is so effective for golf balls, why is it not used on formula 1 cars for instance?

Does anyone have any insight?

[Janus]

Golf balls by necessity are spherical.  A sphere has a drag coefficient of 0.47.  Adding the dimples can reduce this by about 1/2.
a streamlined (non-spherical) object can have a drag coefficient as low as 0.04. 

The point is that Adding dimples to the sphere works because there is a fair amount of room for improvement, and adding dimples is a way of improving things with out having to change its basic shape.   A streamlined body on the other hand, has a shape that is chosen to be at the limit of reduced drag coefficient, and altering it by adding dimples is more likely to make things worse rather than better.
It's like in cooking. Adding salt can improve the taste of a bland dish,  But if you start with something which already has the optimum amount of salt, adding more salt can ruin it.

[RD]

[Petrochemicals]

Darren asked this question:

Golf balls are dimpled to disrupt the air flow around the ball. As far as I can gather this reduces the drag and allows them to fly further than they would if they were perfectly round. Why do we not see dimpled cars, aircraft or trains? If this effect is so effective for golf balls, why is it not used on formula 1 cars for instance?

Does anyone have any insight?

I believe the dimples on a golfball are designed to create a vortex above the surface to lower pressure at the surface, sort of a cocoon, making the golfball stay aloft longer rather than aerodynamic profiling. Wings for a sphere essentially, planes would have alot less drag without wings, but just like a golfball they wouldnt get as far.

Formula one cars aerodynamics are not designed for flight rather to keep them on the surface, to such a degree they can drive on the ceiling at high speed.