If we continue to let market and speculative forces establish the price as world oil (energy) production declines, we will continue to see price spikes. Maybe not as quickly or as high because there are far fewer consumers who can bid the price back up. No one knows how and when this will play out, but it is certain that there will be less gasoline as oil production, the predominate part of finite input energy, inexorably declines. The tragedy of this inevitable scenario is that the love of the automobile trip, especially by those left who can afford gasoline even at a higher price, will deny increasingly valuable energy for more essential needs. Already this is happening with ethanol and bio-diesel.  

   Increased taxation of transportation fuel, as practiced for years in other industrialized countries, is a step in the right direction but not much better than when only market forces balance price, supply, and demand.  The wealthy can still outbid the poor. On the positive side, at least increased taxes encourage smaller cars and reduced travel by all, the price is somewhat stabilized, and some of the fuel cost flows to the national treasury.

THE BACKGROUND (in numbers and simple physics):

   Presently, in very rounded numbers, two-hundred million licensed U.S. drivers consume each day four-hundred million gallons of gasoline (ten million 42-gallon barrels). This gives every driver an average of two gallons or at twenty-five miles per gallon, fifty miles of travel ... each day! This quantity represents one-eighth of world oil production just for American gasoline. Does this level of gross energy consumption justify the premature demise of our energy-intensive civilization?

   If all drivers were restrained equally in gasoline use, there are a number of ways overall consumption could decline WITHOUT ANY initial reduction in distance traveled. For instance, let’s focus on the simple physics involved for transportation, starting with the basic principal which everybody should understand:

W = F x D

   Work (W) output is equal to the fuel (energy) used in the engine, minus heat losses, to provide the force (F) required to move the car, times the distance (D) traveled.

   We can easily reduce the left-side fuel required to provide the necessary work (W) without reducing distance (D) by decreasing only the force (F) on the right side. This could initially leave the distance traveled (D) unchanged.

   For driving on the level, (F) consists of only two significant drag forces that require work (as fuel-energy) to overcome: rolling (R)and air turbulence (T). (T) might also be called wind resistance or air drag. (T) and (R) represent energy lost as heat, forever, from pushing air molecules aside as the car passes through the air or flexing the tire over an uneven surface.

In algebraic terms:

F = R + T

   If we take a minute to further investigate these two terms, it will clear up much confusion, bogus information, and save a lot of fuel.

   Rolling drag (R) is simply a numerical measured coefficient for a type of wheel (on a specific surface) times the weight on the wheel. For a hard rubber tire on pavement it is about 0.015 times the weight on the wheel.  If the tire pressure is increased, this coefficient is less. If vehicle weight is less, rolling resistance (R) is also reduced. This is why bike tires are pumped up hard, and bikes work easiest on hard pavement. Lighter vehicles use less fuel. That’s all there is to it. Not much we can do here except use a lighter vehicle or pump up the tires for a few percent reduction in fuel consumption.

   Air drag (T for turbulence) is a little more complicated but needs to be clearly understood regardless of how we move into a low-energy future and especially with electric cars which have very little energy onboard.  Here is where we can make significant reductions of work (fuel) required and are presently terribly wasteful.

   There are three important factors multiplied together to make up the air drag (T). At very high altitudes thinner air also reduces air turbulence, but we will ignore that factor for our analysis. The total equation for air drag is:

T = A x S x V(squared)

   The frontal area of a vehicle is (A). Simply put, a vehicle with twice the frontal area will have twice the air drag. This is why airplanes are packaged like a cigar and travel in thinner air, and bicyclists crouch down to go fast. Yet, we insist on driving cars as big as barn doors because fuel has been so plentiful and inexpensive for the last 100 years. Smaller cars would immediately save a lot of work (fuel).

   The second term (S) is a measured factor, which defines the shape of the vehicle and the way air (wind) flows around it. Intuitively we know that a streamlined egg shape will move through the air with less turbulence than a rectangular brick, yet we still waste gas driving cars shaped like one. A modern streamlined car has a shape factor (known as the coefficient of aerodynamic drag) of about 0.3 and there is not much more we can do about this factor except drive well-shaped cars. In addition, both frontal area and shape factor are not significant below speeds of about 30 mph when the total air turbulence (T) is small and less than rolling drag (R). We don’t worry about shape and frontal area while pushing a baby carriage.

   This brings us to our third factor, speed or velocity (V). This is the most important of all three terms because it is squared. If we go twice as fast (churning and heating air) it becomes four times as restrictive. (Two squared equals two times two equals four.) Do we really need to drive fast to get somewhere a little sooner? Only rationing will encourage slower driving because speed will use up the coupons quicker over a shorter distance. 

   The three terms (A, S, V), multiplied together, constitute the best possibility for considerable immediate fuel savings without an initial  reduction in distance traveled and change in current way of life.  Remember, this is fuel (energy) that is and will be far more critical for our complete energy system such as food, heating oil, social services, commercial transport, national defense, petroleum-based products, and all the other ubiquitous uses of petroleum as a food or feedstock.  Converting coal and natural gas to automotive fuel, converting to diesel passenger cars, or plugging in hybrids only avoids the issue by substituting other TEMPORARY-FINITE energy inputs and moves us farther down ... the wrong road.

   Rationing would dictate changes in driving habits equitably between rich and poor. No other concept gives us such a significant energy impact reduction for our future survival, yet it needs to be legislated so all share the effort. We need to get started while we still have considerable energy left but less every year.

   In the not-too-distant future, when reduced speed and smaller cars are not enough, we will obviously have to drive less, plus shorter distances as restricted by increased rationing. This writer remembers World War II when our family had coupons for three gallons per week. That was a clear, temporary, national emergency at a time when the U.S. produced most of the world’s oil and fueled the war. The collapse of our short oil age and termination of one-hundred and fifty years of steady growth appears even more perilous.

NEXT: Implementation

Gasoline Rationing . . Are You Kidding?