Auto Autopilot Decision – MPG vrs. GPHM – The Unseen Impact

Many definitions like MPG are deeply ingrained in society. The decision to base this accelerated federal mandate on MPG was simply an autopilot one.

CAFE (Corporate Average Fuel Economy) standards are based on a wide range of factors, including what is technically possible at a "reasonable" cost. The affect these standards have on a buyer's purchasing decision has regrettably not always been a key factor. Continuing to set fuel-economy standards in MPG will, however, predictably create unintended consequences. What really matters for car buyers, but more importantly the U.S. economy and the environment is actual gas usage not miles per gallon. Usage is best defined based on gallons [used] per hundred miles (GPHM) not MPG.

There has been research into using an alternative definition for auto fuel efficiency- GPHM by both Duke University and by a Washington, D.C. think tank – RESOURCES for the Future. Both found that most other countries measure not MPG or an equivalent, but how many standard units of fuel are used to drive a specified distance? This is also precedent setting; just not American precedent.

The likely and unintended consequences of the MPG decision are significant. In the upcoming decade consumers with only smaller, more expensive cars from which to choose are more likely to keep on driving older, larger, more polluting and less fuel-efficient cars much longer.

Car companies whose domestic market is comprised of smaller cars like the Japanese are also likely to benefit more from Obama's plan because they are better positioned to produce smaller cars.

This decision may ultimately also result in both more lives lost on U.S. highways and an increase in medical service usage since auto accident deaths increase as vehicle size decreases. This is another important issue that is again a non-factor in setting CAFE MPG standards. Of course, improved auto safety technologies should diminish this affect over time; all things being equal.

If the overreaching U.S. goals are to reduce carbon dioxide emissions while using less oil then the best solution would be for Americans to drive fewer miles in more fuel efficient autos. The quickest way, however, to accomplish this is to dramatically raise the price of oil by hiking taxes. The alternative and considerably less politically difficult approach is to remove or replace as many of the worst fuel inefficient vehicles as possible. By choosing to measure our progress in GPHM used rather than MPG the odds of reaching the latter would significantly improve.

Using GPHM would also shift the focus toward all the vehicles on the road, which ultimately could result in tax and other incentives to push clunkers, gas guzzlers and the worst polluters off U.S. roads. GPHM also helps everyone better understand the true pocket book implications of trading one car for another or purchasing a new or used vehicle.

Definitions matter in often unforeseen ways. Open4Definition raises yet another question. What would the impact be if this auto fuel efficiency mandate were stated, for example, in terms like gallons per hundred miles traveled safely? GPHM is significantly better than MPG, but there are likely even better definitions and measures of auto effectiveness (not just efficiency) available. It would make sense to systematically choose the best of the best.

Change can be compromised when the selection of the definitions used in critical public policies are chosen on autopilot. All too often what we define is what we get. Wouldn't it just make sense to pay more attention to the definitions used? Obviously, Open4Definition believes that it would. Let's take auto fuel consumption policy off autopilot. Now that would be change to revel in.

Click to read the Open4Definition article also on this subject.