0.3%

According to a show on the Science Channel I was watching this weekend, 0.3% is about how much of gasoline's chemical potential energy goes into moving your (or a passenger's) body in the typical automobile. The remainder, of course, is lost to pushing air, moving a few tons of metal, friction and heat in the engine, tires, a/c, etc.

I found myself the victim of an obligatory science experiment this morning. Pam noticed one of the tires on our Dodge Durango was low... Must be a slow leak, I reasoned. Being a bicycle enthusiast,I have a couple of standard bicycle pumps around, but I've never invested in an air compressor. Recently, the tire on my Honda Civic Hybrid was low, and I topped it off with the bike pump... it took a while... but it worked.

So, I gave it a shot with the SUV. Oye.. my achin' back! It turns out if takes a lot of spirited effort to inflate an SUV tire with your standard bicycle pump. The following table summarizes my efforts to inflate various vehicle tires I own:

Vehicle	Weight	Tire PSI	Pump Strokes
Road bike	15-20 lbs.	120	2-5
Mountain Bike	20-30 lbs.	65	10-12
1Kw Electric Scooter	85 lbs.	35	15-20
Passenger Car	2749lbs.	32	~200
SUV	4568 lbs.	31	~600

From the table above, 2/600 pump strokes = 0.3%! Similarly, I've heard calculations of casual human power on a bike being around 1/3 horsepower. Your typical small compact car has just over 100 HP. That's about 0.3%!

Gasoline-powered automobiles have been cruising down the road for about 100 years now. The original Model-T got about 25 MPG. The average car today gets about 25 MPG. You'd think with all the technical advances we've made in the last 100 years, the efficiency of our autos would have improved more dramatically, but I think I finally understand the problem.

You see, with a few notable exceptions, automotive engineers must have been confused... and thought they could only improve by 0.3% instead of 99.7%, so they just gave up. Simple mistake, really... I suppose we could just take matters into our own hands and make our lives 99.7% easier by riding bicycles.