[TestDrive]

Originally Posted by aerohead

And the long answer to the question stands on the evidence,yes,aerodynamics directly impacts BSFC.

Isn't this conflating BSFC (of the engine) with the BSFE and most Optimally FE Cruise Speed (of the vehicle).

Referring to the first chart in the http://ecomodder.com/forum/showthrea...-got-1466.html


I see FUEL CONSUMPTION mapped against engine RPM and TORQUE - nothing involving GEAR RATIOS or MPH.

Originally Posted by MazdaMatt

So in effect... reducing drag means reduced HP requirement. In order to cruise at the same speed with the different HP you have a lower throttle position. Lower TP at the same RPM puts your engine in a less efficient point on the BSFC chart?

Assuming the cruise speed in question was already optimally FE prior to the reduction in drag, I think that sums it up nicely.

Of course assuming that the initial cruise speed was already optimally FE can hardly be considered a given. For both my '94 Escort 5sp MT and my '99 Escort 4-door 5sp MT, the most optimally FE cruise speed is about 37 MPH !!!