It's easy to calculate and track your fuel economy in OpenOffice.org Calc. Gas is not getting any cheaper, so you may wish to continuously monitor your car's usage and efficiency as part of your budget. Before you begin To get good results, you must start with good data. Each time you get gas, follow these steps:

1. Fill your tank all the way up.
2. Get a receipt.
3. Verify the receipt shows the number of gallons¹ you pumped.
4. Write the value from your trip odometer on your receipt.
5. Reset your trip odometer to zero.

Note: Step #4 only works the second time through this procedure. The purpose is to measure how much gas you used (step #) and how far you went with that gas (step #4). In the spreadsheet

1. Start OpenOffice.org Calc
2. In cell A1, type Date.
3. In cell B1, type Trip odometer (miles).
4. In cell C1, type Gas pumped (gallons).
5. In cell D1, type Economy (mpg).
6. Below the first row, fill out the data (in just the first three columns).
7. In cell D2, type the formula =B2/C2 .
8. Select D2.
9. Press the copy button on the toolbar (to copy the cell to the clipboard).
10. Highlight D3 and below. Go down as far as you have rows of data.
11. Press the paste button on the toolbar. (This step propagates the formula for each row.)

Calculating cost per distance How much does it cost you to travel one mile (or kilometer)?

1. In cell E1, type Price ($).
2. In cell F1, type Price ($) per mile.
3. Fill out columns E and F with data.
4. In cell F2, type the formula =E2/B2 .
5. Copy cell F2 to the clipboard.
6. Highlight cells F3 and below.
7. Paste.
8. Click column F (right on the letter itself) to highlight all the cells in it.
9. (optional) Click the currency button on the toolbar.
10. (optional) Click the Number format: Add Decimal Place on the toolbar.

Exercises for the reader

• Write a formula to calculate average fuel economy.
• Write a formula to calculate average miles per day. (Hint: You will need to use data from two rows.)

Tips

• Look for anomalies, and try to explain them. Did you change your driving habits? Does your vehicle require repair?
• Wikipedia: Fuel economy-maximizing behaviors
• wikiHow: How to Increase Fuel Mileage on a Car

¹ Metric users To 99.5% of the planet, please excuse the imperial units. Yes, they are obsolete. Kindly contain your disdain while substituting liters for gallons, kilometers for miles, and $ for your local currency. :)