Re: My new EV website... MGB Aero

["PETER VANDERWAL" <peterv@peoplepc.com>]

> Hello Mr. Dycus and Mr. Walter,
>
> A truck accessory manufacturer tests his products by
> simply letting his test vehicle roll down a long or
> steep hill onto a flat, and measures how far each
> product allowed the truck to roll in comparison to the
> stock truck, and the rest of his products.  I may try
> that myself to see if my aerodynamic undersheeting,
> bed cover and nose cover are actually worth thier
> weight.

Ah yes, the roll down test.  A slightly better method is to pick a long
stretch of reasonably flat road, accelerate the vehicle to a set speed (say
60 mph) and then time how long it takes to roll to a stop or a lower set
speed (say 30 mph); to a stop is more accurate.  Repeat the test in the
other direction to cancel out the effects of any wind (it's difficult to
cancel out wind on a hill test).

There are actually some formulas that estimate aero and rolling drag from
this type of test, however who cares?  If you roll further it's better and
that all that really counts.