Better manage your gas dollars: start using GPM rather than MPG!

Professors Rick Larrick and Jack Soll, researchers at Duke University, have shown how a simple mathematical change in measuring gas mileage will help consumers: measuring usage in gallons per mile (gpm) rather than miles per gallon (MPG) as we do today. For further mathematical convenience, you can measure gallons per hundred miles.

Hence, if a car gives 20 miles/gallon, that would mean that one mile requires 0.05 gallons or that 100 miles requires 5 gallons. At today's rate of $4/gallon, that is about $ 20. Similarly, if a car gave 40 miles/gallon, then it would cost only $ 10 to cover 100 miles. If a typical driver drove 100 miles a week, their gas consumption would be $ 40 instead of $ 80, pointing to a clear saving of almost $ 500/year. For the mathematically inclined, more details of the non-linearity can be found at http://faculty.fuqua.duke.edu/~larrick/bio/Reshighlights.htm.

To change this, however, we do not need a 100 million dollars and a federal mandate. To see your car's efficiency in miles/100 gallons, check this calculator.

Another elegant way to see this graphically is shown by AJ Design software:


I am getting the correct usage for my car anyway by either calculation. Why should i care?

True enough. When you compare two cars, the difference will not change. Based on this calculator, a Ford Explorer that gives 15 mpg will, over 50,000 miles, require 3333 gallons more oil, which at $ 4 per gallon, translates to a cool $ 13,000. A Ford Escort at 30 mpg on the other hand, will only cost $ 6600. This is certainly easier to calculate if we use gpm rather than mpg.

More interestingly, however, if we compare the savings in going from 10 mpg to 20 mpg as opposed to going from 30 mpg to 50 mpg, the Duke research shows that the move from 10 to 20 mpg will save a lot more than by going from 30 to 50 mpg.

Beyond the mathematical interest in how numbers are not necessarily what they may seem, this is a fascinating subject because it goes to the heart of capitalism: measuring value in dollars and cents. The next step: use this calculator from AJDesigner.com to get the cost of any form of energy over 50,000 miles. Take away the subsidies that Big Oil gets and we could have a fascinating insight into true costs of energy.

What if Russert had died 6 months earlier?

Now that some time has passed since Russert's passing, it is time for us to evaluate his true impact on this Presidential election. If Tim Russert had died six months earlier, Hillary might have been the Democratic candidate. Just a thought . . . in general, he was her toughest questioner for months, if not years.

He was the pundit who asked the first question on drivers licenses to illegal immigrants and he was the one who first indicated that the Democratic nominee was known and that the race was over.

The underlying Washington talk behind all this is that the media disliked Hillary Clintons because of her prima donna attitudes for several months when she was seen as the inevitable front-runner. The difference was that while others like Keith Olbermann and Rush Limbaugh attacked her personally, Russert went after her while still retaining substantive policy issues on his agenda. This is a testament as much to his skills as a journalist as his overall lack of partisanship.

In the end, the nomination was Clinton's to lose and guess what? She did.