Brain Hack : Gallons per 100
When we describe the relative efficiency of an automobile, we almost always use the measurement of miles per gallon. It’s easy to describe, it’s easy to calculate, it’s familiar. But is it the appropriate measurement for comparison?
Mathematically, it’s perfectly reasonable. Using the measure of MPG, I can tell you exactly how many miles I can drive on a tank of gas, or how many gallons I’ll burn driving a certain number of miles. Unfortunately, the human brain isn’t a perfect computer and we often take shortcuts in calculations.
Consider the following graph:
This simple chart shows the relative MPG for four sample cars. Each car in the series gets 10 MPG better than the previous. Looking at this chart, you might conclude that the difference between Car A and Car B is equivalent to that of Cars C & D.
Surprisingly, you would be wrong.
Here is the same data but represented in Gallons per 100 Miles:
Looking at this graph, it’s immediately obvious that the difference between Cars A & B is far greater than Cars C & D. After driving 100 miles, Car A burns 2.6 gallons more than Car B; Car C burns only 0.6 gallons more than Car D.
So why is this important?
As high fuel prices and increasing environmental awareness push consumers towards more efficient automobiles, it’s important that we have an accurate comparison. If you drive a car that gets 20 MPG or less, upgrading to a car that gets 25-30MPG will have a significant impact on your fuel consumption. Far more, in fact, than upgrading a modestly efficient car to a super-efficient model.
Hack your brain–next time you’re comparing cars, don’t look at MPGs. Convert to Gallons per 100 Miles (GP100) instead and make your comparison much easier.
GP100 = 100 ÷ MPG
Filed under energy, hack : Comments (2) : Mar 17th, 2009 by tadfad
March 24th, 2009 at 18:10
Not surprisingly, Europe’s been wise to this hack for years (although in liters per 100 km).
Check out this Irish fuel economy label. Link.
March 27th, 2009 at 19:19
interesting. so much is how it’s framed.