[FormulaLosAngeles]

thank you for considering the implications, multiplying payload fraction by range prevents claiming only the good statistics in advertising, and hiding the bad statistics, since it combines all the factors, however rudely and imperfectly. (non propulsive heat recovery utility is not really numerable at this time , but that does not mean we should not exploit that which we cannot measure well). The numbers might show it is better to take the bus, but we knew that, and we don't want to take the bus.
It is meant to be a comparison number we can rapidly collect, and even if not perfectly defined or accurate, it can show gross comparisons of utility which may be so great as to render the need for perfection irrelevant. An 'Acid Ratio' in accounting is similar and refers to previous acid testing of gold purity. If your payload fraction is low, you lose some efficiency, be it from a diesel iron block or scads of batteries etc. If your range is terrible you have either poor utility or poor efficiency. multiply the two and the truth cannot be hidden. The weight and range should in the glove box manual for safety reasons by law and the car can be weighed at low cost.

there was an error in the formula which I edited to this below, ((max allowable Gross weight-Net or tare or empty or Curb weight)/max allowable Gross weight) x range = number + (waste heat utility) = non dimensional number or score. An airplane might have an 'Oswald number' made up by .. Oswald. I'm francis, I'm old enough now, I made up a number, I get to name it the Francis number because I am pissed off about bad design that hides by omitted disclosure, which is the definition of fraud.