RainGuards
 

i was wondering if putting rainguards on my car would help reduce drag when my windows are down

It might, but why would you ever roll your windows down?

However, I'm tempted to say it might not, since it prolly just redirects swirly air out to the side of the car...

ide say yes being the smoker that u are it should help because if u just crack your window instead of having your window all the way down it will block most of that air from comeing in.

I did a test on my Geo Metro recently and found that unrolling the windows @ 50mph only saw a 1 mpg (1.8%) decrease in FE. In my opinion, it doesn't make enough difference to prevent me from keeping the windows open on hot days (since my car dosen't have A/C... and you'd bet that A/C would drag my FE down a lot further than just 1 mpg at that speed).

I actually want to take my dad's Intrepid out sometime and do the same test. Figure out the speed one has to attain for A/C usage to offset the aero drag caused by opened windows.

Traugbot -

On my Saturn, I needed them for the rain. On the freeway above 35 MPH, I use them to crack the window on a hot day in LA. That way I get ventilation but I *hope* less aero-penalty. They definitely are worth it for me. I have a four door, but I only got two for the front windows.

CarloSW2

i think that they would be good investment because i hate to use AC and i do smoke so they do sound like a good idea. thanks for all of the input guys