Not MPG - GP1kM

That's Gallons Pr. 1000 Miles - a better way to understand fuel savings. Why? Because most people (including me) imagine fuel savings as linear, meaning that every 1 MPG saved is less gas used no matter your vehicle. So going from 25 mpg to 50 mpg should save more than going from 10 mpg to 20 right? Not true, and you can see why in this video from Duke University:



Here is a graph shoing how many gallons you use over 1000 miles in cars ranging from 10 to 100 MPG. As you can see, it gets exponentially more difficult to achieve a 50% reduction in fuel usage.



Of course, if you can go from 10 mpg to 50 mpg that would be the best, but if you have the option of upgrading one of two cars, go for the low MPG one first!