Hey Ken,
If you haven't read 'The Leading Edge' by Goro Tomai, you should. The less rolling resistance claim is a sum of all of the forces, tire forces, bearing windage losses, brake drag, etc.
Also, the loss equation for a tire is not a linear equation, but a second order to try and take into account the hysteresis losses......that is, there is more loss from than 4th tire vs just three discounting the other losses mentioned above.
It is a fantastic book and Goro was kind enough to converse with me to answer questions about different equations.
SteveF
Quote:
Originally Posted by Ken Fry
The Aptera claim was something like this: "...and of course three wheels have less rolling resistance than four." That's incorrect, unless they are saying that the vehicle is lighter, and therefore has lower rolling resistance.
Three wheelers (aside from the side car arrangement) pick up the additional frontal area of the third wheel, whereas the rear wheels of a four-wheel car are in the wind shadow of the fronts.
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