As some of you may have noticed, gasoline is now over $4.00 per gallon in the United States, and if that hasn't motivated you to drive less, maybe this will. Your car is only 1% efficient.
That's right, out of the $4 it now costs for a gallon of gasoline (if you can still find it for $4), only 4 cents is actually being put to use getting you around. The other $3.96 is being lost to thermal efficiency and moving a 3000+ pound vehicle.
Let that sink in for a moment. As politicians debate an 18.4 cent gas holiday, off-shore drilling, and a 35mpg CAFE standard that won't take effect until 2020, we're ignoring a much bigger problem. That the automobile is possibly the LEAST efficient way to move a single person around.
Getting to 1%
If we say a gallon of gasoline has 100 units of energy (and ignoring the embodied energy required to produce and deliver it to the pumps), burning it in an internal combustion engine converts only 20% into rotational energy (for diesel engines it's roughly 30%). So from the original 100 units, we are already down to 20. Of those 20, another 15-20% is lost to drivetrain friction. That leaves 17 units actually being put to use driving the car. With most vehicles now over 3000 pounds, the individual inside is only about 6% of the total load, and therefore only using 1% of the energy.
That's 1% of the energy delivered at the pump. If you start calculating the energy that goes into producing the car, the gallon of gas, shipping it to market, the roads, parking spaces, garages, etc. you're talking about very small fractions of a percent.
If we are serious about fuel conservation we have to be serious about driving less, in addition to improving fuel efficiency, and converting to alternative energy. The more we continue to encourage driving, the more we are forced to drive. More cars require more roads, more parking, and longer distances to be driven, meaning more cars more parking, and less effective mass transit and other alternatives. Most of our planning policies are based on a cheap oil era, with a near total reliance on automobiles to get us between buildings sited in single use zones. Our planning policies generally discourage mixed use, walkable, or transit oriented developments, except in rare cases, and need to brought into line with the current and future economic realities of energy.