Quote:
Originally Posted by Old Tele man
∞MPG = MILES / 0 gal.
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Some BEV drivers use the same logic to claim ∞MPG as well.
I think it is better to do a MPGe comparison instead ... weather it be pollution based , energy based, or cost based ... use level or complete product life cycle .... although energy based is my preference... and use level is much easier.
The additional exercise from pedaling will burn additional food calories of energy , and cost additional $ for the food to get those food calories... more than what would be spent being more stationary.
Grabbing some easy numbers from Wikipedia and such to get a basic idea... better sources may yield some better numbers.
A food Calorie is = to a scientific kilo-calorie = ~1.163 wh per food calorie
The Human body is not 100% efficient ... and peaks out around ~27% at converting chemical food energy into mechanical energy.
If we averaging closer to about ~20% ... ~500 food calories consumed per hour of bicycling at an average speed of ~12 mph ... of course YMMV different routes methods speeds and rider metabolisms etc ... This is about ~117 Watts of mechanical power or ~117 wh per hour mechanical.
500 food calories = ~581 wh of chemical energy consumed per hour to travel 12 miles at the 12 MPH rate... or ~48 wh of chemical energy per mile.
At ~36kwh of chemical energy per gallon of gasoline ... this 12 MPH speed works out to about equal to ~750 MPGe from a use level energy input perspective... YMMV of course.
Still phenomenal ... and while the use level does not include some of the life cycle costs end effects ... including the upstream energy costs of getting those food calories etc ... there are also other life cycle benefits to the regular exercise the bicycling gives and the $ that is saved on avoiding automotive expenses.