Tool for visualizing aero vs rolling resistance

[MetroMPG]

Originally Posted by JanGeo

Actually I have heard that you can ignore the CD Drag Coeffient at lower speeds (under 100mph) as it is such a small portion of the rolling resistance and frontal area drag as to not matter much.

100 mph? (hopefully i'm misunderstanding your point. you're not saying that aero drag is unimportant below 100, are you?)

have a look at the spreadsheet or the web page and you'll see the aero penalty begins to rear its ugly head relative to rolling resistance at between 30-35 MPH.

http://metrompg.com/tool-aero-rr.htm

below that speed you burn most of your fuel to overcome rolling & mechanical drag.

above 35 mph, you burn most of your fuel fighting a losing battle against aerodynamic drag.

(a "losing" battle because the amount of fuel needed to overcome aero drag quadruples as speed doubles.)