## Sep 28, 2007

### New Tank Record

I drive a hybrid - a Toyota Prius. For the last year or so, I've had a bike rack attached to the (custom installed) trailer hitch which I didn't bother to remove when driving around. I finally got around to removing it during my last tank of gas. I went and made sure my tires were inflated, removed unneeded heavy crap from my car, and didn't use much A/C (the weather has been good). Today the experiment ended as I had to fill up again.

My goal: maximize my MPG for this tank.

Result: 475 miles even on one tank of 8.814 gallons = 53.9 MPG

I was hoping to get to 500 miles on the tank. I probably could have, I think the tank is 10 or 11 gallons, but the gauge was showing me the blinky bar wednesday (2 days ago) which means that the Prius won't tell you how much you have left any more. Interestingly, I didn't have the rack off for the entire tank, maybe about half of it, so I'm interested in seeing how well I can do on my next tank.

#### 1 comment:

Brian said...

A good way to calculate your mileage if you really want to be accurate as in this case is to do the following:
- Record your total mileage the next time you fill up your tank.
- Be sure to fill the tank as much as possible.
- Drive your car whatever number of miles you choose, taking careful note of the general terrain over which you are driving.
- Return to the same pump at the same gas station and fill your tank. Again, fill it as much as possible and note the total mileage as well as total gallons required to fill it. The reason for using the same pump as the first time you filled it is to eliminate the variable that the car may set at a different angle at different pumps, thus allowing you to fill it more or less than the first time.
- Divide the number of miles driven since the last fill up by the number of miles driven since the first fill up.
- To check the repeatability of your gas mileage result, repeat the experiment, ideally following the same route as before, such as predominantly driving only to and from work during the experiment.

Happy calculating!