Originally Posted by flyboy1100
Just a quick comment here, I agree with a lot of your points of your whole post. But the first question there is a vortex generator on the back of the roof rail to offset the fresh created by the rails
I've seen the video with the Subaru spokes person claiming that the little tail stub at the end of roof rail improve the mpg by 1.
I don't think there was any claim that the little stub completely offsets the mpg cost of the adding the rails.
Anyway, maybe all these things are within margin of error, or they are all fractions of mpg numbers so the don't ever show up when you look at each of these individually.
But if you look at all the things I mentioned, the sum of all these difference has to amount to some MPG difference, yet we see NO DIFFERENCE.