Jim Kelly from PriusChat.com Discusses Hypermiling with Richmond NBC Affiliate

Basic calculation for determining alternate route benefits

I thought I'd share a basic calculation, which I use all the time, but I thought might be helpful to those who are not as mathematically inclined as others.

I used to wonder if taking another route to work would result in better fuel efficiency. One thing to consider when asking yourself this question is, is the increase on your MFD actually worth the additional mileage?

From a monetary perspective, one could argue more miles means more maintenance costs, but let's ignore that one. Let's say the only factor in determining your route of choice is the amount of fuel it costs you to go route A or route B.

Let's use the following as an example:

Route A: Normal work route - 20 miles - 50.5mpg
Route B: Alternate route - 27.2 miles - ???

Given the above, we know how much fuel we burn each day going Route A: 20 / 50.5 = 0.3960 gallons

To make Route B equal/more beneficial [in terms of gallons burned] you must burn the same, or less gallons during your 27.2 mile trip as you would on your 20 mile trip.

To determine this, you take the total miles of Route B and divide it by the total gallons burned to get your resulting route MPG required to make it beneficial: 27.2 / 0.3960 = 68.69mpg.

So what does all that mean? In order for you to burn the same [or less] amount of fuel driving Route B, you would need to get 68.69mpg or better to make it worthwhile.

I hope this helps, I know some of you like to play around and figure out what distances will get you the best mileage, but there are also other factors to consider when trying to get the best FE.... hopefully this will shed some light.