Roof bars/racks. Which is more aerodynamic?

[alittlebitconcerned]

Just a thought experiment...

Which would be more aerodynamic on a 110 defender? (Yeah I know)
3 to 4 typical crossbars sitting approx 100mm off the roof, or a thin full length alloy roof rack that sits ALMOST on the roof and follows the contour of the roof very closely, with minimal space/gaps between the members?

What say you?

[JDNSW]

Almost certainly the second - but the actual drag will depend on what you are carrying, and you should remove the rack when not carrying anything - and you can probably carry the bars internally, which you definitely can't the rack.

[alittlebitconcerned]

I use my 3 x roof bars every week with my work so although I agree taking them off is best it’s not an option unfortunately.

I also have a full length alloy rack that I’m considering putting on very short legs and cutting and welding it to follow the roof contour hence the thought experiment.

glad to hear you think the rack option would be the most aerodynamic as it is the most versatile.

Anyone think differently?