Quote:
Originally Posted by aerohead
optiwatch,sorry! I'm way late to the party.I ran your numbers for 70 mph and got 19.1 horsepower aero load at that velocity.I used 0.00238 slugs/ft cubed for density,102.67 feet per second velocity,Cd 0.32,and 25.5 ftsquare for frontal area.Sorry,as yet,don't have my estimation stuff for rolling resistance with me.I don't know if your formula also simultaneously figures rolling resistance horsepower.I stuck with what I'm familiar with.Also ,apologize to members for the US Standard notation.I'll put some conversion stuff together and try and post metric units in future.Its tough living in the stone age!

Those numbers sound reasonable. I used the spreadsheet and tried to stick with metric and I got 3.4 kw @ 35 mph and 10.3 kW @ 100 mph, which translates to 4.5 and 13.8 hp. Maybe I got some conversions wrong though.
slugs! *groans*
I always thought it was v^2 not v^3, just from what I remember from my fluid mechanics class.