The Idea Hunter's blog

Thoughts on better thinking and better presenting

Doing your bit to reduce petrol consumption

Quick question for you:

Let's say your goal is to reduce petrol consumption.

And let's say there are only two kinds of cars in the world. Half of them are Suburbans that get 10 miles to the gallon and half are Priuses that get 50.

If we assume that all the cars drive the same number of miles, which would be a better investment:

  • Get new tires for all the Suburbans and increase their mileage a bit to 13 miles per gallon.
  • Replace all the Priuses and rewire them to get 100 miles per gallon (doubling their average!)

This is from a recent post by Seth Godin highlighting a counter-intuitive arithmetical question. On first inspection it seems that option 2 is the best but work through an example and prove to yourself that option 1 saves more than double the amount of petrol.