I see where you guys are headed with the *no improvement* comment I made on the roof rails. To be fair, I should have stated no perceptible improvement which mirrors MetroMPGs corrections. If I had crossbars and mounts, I'm sure there would have been a more noticeable change but even without that, I'm sure there was *some* change.
However, just to satisfy my curiosity, how do "we know" that removing side rails on every make and model actually offers an improvement? The imperceptible difference that I didn't notice could have just as easily been negative, no? I mean, that weird 90s NASA study shows great improvements in MPG by ADDING things to the front and top of cars and vans that appear to mimic what my roof rails might do. They seemed to indicate that some shapes tend to do better if the air is directed over the top of the car and around the sides of the car - if the airflow is split properly - which many of the mods I've seen on this site help with, and so isn't it entirely possible that having a well designed roof side rail on a specific shape of car could actually "help"?
Sorry for the run on sentence and the devils-advocate question but it seems to me that many european cars come with siderails (only siderails, no crossbars) and so thought and windtunnel time might be put into their design and placement so as to use them to the carmakers advantage. Maybe? At the very least, we can say that an aftermarket rail or afterthought of a rack placed on an econobox will surely have more effect when removed than a rail on a car originally designed with a rail in mind?
But I do get the point...it might have helped and if I can find 100 more things to modify that slightly, I might see 1 mpg instead of 0. Point taken. Just not easy to swallow as I was hoping to not have to make 500 ore more small improvements.
. (And burning through 500 tanks to prove them out!)