Roofbars Effect On Mpg

[KAR]

I'm thinking of buying some Ford roof bars for my 2010 Galaxy Zetec 2.0 Powershift. Motoring organisations always advise to remove roof racks, but what about these semi-permanent roof bars? I guess because they are streamlined they will have minimal effect on mpg - but is this assumption correct. Has their effect on mpg ever been measured?

[FOCA]

Hello and welcome to the forum!

According to this test i found, aerodynamic roofbars/ boxes do not make a big difference to MPG -

http://www.autoexpress.co.uk/car-news/31861/mpg-mythbusters

airconditioning (especially around town/ not at a constant higher speed) and extra weight (especially up/ down hills) made a bigger difference / reducing MPG

[KAR]

Thanks for the reply. Very interesting. If a roofbox takes up 0.2 mpg then the roof bars by themselves must take up virtually zero.