The Automobile Gas Log

by Kevin on February 28, 2008

Several years ago I started tracking my gasoline expenses in a paper logbook that I keep in my glove box. I got the tip from a car enthusiast forum as a way to keep a heads up for car issues. I fill it out every time I fill up my gas tank.The logbook tracks:

  • The date
  • Total miles on odometer
  • Total miles on the previous tank of gas
  • Price (per gallon)
  • Total cost
  • Number of gallons

Pretty basic, but it holds a lot of data. If you’ve been reading this blog for a while you know I love spreadsheets. So, you guessed it, I put the data into a spreadsheet. The idea is you can calculate your miles per gallon for the previous tank of gas. If your miles per gallon drops significantly (and your driving habits don’t change), you have a car issue of some kind. It’s a simple tool to help you catch something before it becomes a big problem (maybe your fuel filter needs to be swapped out). Don’t play the poker gamble that you’ll hit the the straight flush with your gas mileage. Don’t assume it’s been the same as when you first got your car. Tracking your mileage can keep you from getting surprised.

I now have data for the past six years — since 2002. There are some interesting trends within the data. Of course, gas prices have risen dramatically. The lowest recorded gas price per gallon I have is from February 2002 at $1.06. Ugh. Gas in our area is now at $3.09 and with oil above $100 barrel may hit $4 this summer.

From 2002 to present, I have averaged 26.255 miles per gallon. Not too shabby. You can tell where I am doing a lot of city driving versus going on long trips with hours on the highway. Sometime in the future I’ll throw up some of the charts that go along with the data.

Do you track your gas mileage in any way?

{ 2 trackbacks }

From Theory To Practice: The Festival of Frugality | I've Paid For This Twice Already...
March 18, 2008 at 3:57 am
How to track Car expenses. . . | the taxguy
August 27, 2008 at 8:19 pm

{ 7 comments }

Roy Strohl February 28, 2008 at 10:50 am

I have been keeping a log on my Palm for two cars and a pickup truck since 2001. Program is called AutoBase and was a share ware. Oh, you can export the results to a spreadsheet much as you described and then delete portions of the files to clean up.

Joel February 28, 2008 at 11:50 am

mymilemarker.com is a great tool to use that basically does the same thing. It asks for your mileage, gallons and $ per gallon. It then goes on to calculate your mpg for the previous tank and gives you projected miles and cost of filling up 1 year from now.

If you use twitter you can tweet your stats or you can go to the mobile site.

Oh, and the best part, it graphs your mpg per week and your mileage.

Stephanie @ PoorerThanYou February 28, 2008 at 3:24 pm

I’ve been doing this since I got my car, using GasBuddy.com. Their fuel logbook feature tracks all of those metrics for me – pretty handy!

Matt February 29, 2008 at 7:38 am

I did this for a while when I was driving a lot but rather than keep track of the mileage myself I used a website to keep track of everything. I don’t recall what it was but it kept track of everything including the gas stations I used. This gas station/price info was pushed onto the site and people were able to find the best deals. I wish I recalled it.

Regardless you get to see some interesting trends when you manage to collect data over such a long period of time. You can even see the impact of wear on your car.

Mark @ TheLocoMono June 7, 2008 at 12:57 pm

I never did account for my mileage up until now when I purchased my first car lease. I have a 3 year 60K miles lease so in a way, it forces me to pay attention to my mileage usage.

I am currently starting to see how I can plan ahead from all the comments here. At the moment, I am just using $5 a gallon X 1667 miles per month (the average I can drive per month under the terms of the lease)to set a budget with.

But it would be nice to have a more concrete data to work with, great post.

Glenn August 26, 2009 at 4:01 pm

I like to use fuelly.com – It’s a good way to track mileage, MPG, and amount spent on gas. Try it!

Finance February 8, 2010 at 4:00 am

Always account your mileage. Track it down and also, the amount spent on gas. Great article!

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