How would these guys know what measure is more effective? They don’t even drive cars.
MPG is more accurate than L/100KM, has better real life application and is easier to calculate.
Maybe Newtons of force applied per second derived from each Milli-Liter of gas burned at standard atmospheric pressure at sea level.
Consumers can convert to the form that best suits them and polish up on their math skills at the same time!
I've lived in both. Both are accurate, and both are easy to calculate in your head.
The article is talking about this as a relative representation of fuel consumption. As it says, going 10 to 20 mpg doesn't look like you save as much as going from 33 to 50 mpg. After all, one gives you 10 mpg and the other gives you 17 mpg. Most people do fail that little test.
The other way makes consumption comparisons more intuitive. Let's restate it with the equivalents. Instead of 10-20 mpg, you go from 24 l/100km to 12 l/100km. The number cut in half, so it's obvious your fuel consumption gets cut in half. Now go from 33-50 mpg, which is 7 l/100km to 5 l/100km. The number goes a bit lower, so it's obvious you're just getting somewhat better mileage, not as big an improvement as in the first case. The confusion of the mpg system isn't there.
The reason is simple. Our mpg system is based on "how far you can go," while the other is based on "how much you use." Even though either can be flipped to calculate the other way, the volume/distance measure makes the results of "how much you use" calculations more obvious and intuitive.