🚀 go-pugleaf

> But we can at least begin with the fact that if I drive to work I need to
> accellerate and decelerate several thousand pounds of metal while if I
> go by bike I'm only dealing with my own weight plus 25 lbs.  This difference
> dwarfs the human body's being a "notoriously inefficient converter[] of 
> energy", and is responsible for estimates that a bicyclist, if he could
> run on gas, would get upwards of 1500 miles per gallon.

Doing this calculation would be easy if someone can come up with a figure for
the energy content (in Calories) of a gallon of gasoline (if I recall from a
similar comparision done some time ago, the figure is in the 10's or 100's of
thousands of Calories). Using a chart recently published in Bicycling Magazine
(May '92, page 55), energy consumption for a 180 lb rider is:

	@10 mph:  6.39 cal/min * 6.00 min/mile = 38.34 cal/mile
	@12 mph:  7.67 cal/min * 5.00 min/mile = 38.35 cal/mile
	@14 mph:  9.22 cal/min * 4.28 min/mile = 39.46 cal/mile 
	@15 mph: 10.10 cal/min * 4.00 min/mile = 40.40 cal/mile
	@16 mph: 11.07 cal/min * 3.75 min/mile = 41.51 cal/mile
	@17 mph: 12.20 cal/min * 3.52 min/mile = 42.94 cal/mile
	@18 mph: 13.32 cal/min * 3.33 min/mile = 44.35 cal/mile
	@19 mph: 14.60 cal/min * 3.19 min/mile = 45.99 cal/mile
	@20 mph: 16.04 cal/min * 3.00 min/mile = 48.12 cal/mile

To adjust for hilly terrain, add 22 cal per 100 ft of altitude gain.

Given the above-requested calorie content of a gallon of gas, along with the
fuel efficiency rating of a car, equivalent figures can easily be calculated
(some adjustment may need to be made for very short trips, given the known
efficiencies of car operation for such trips).

	--Vince