I keep track of my fuel economy with every fill-up. It’s a little obsessive, I know, but I’ve learned quite a lot from seeing the differences in economy between cars, drivers, seasons, tyres, etc. There is good research to show that when people are aware of consumption, they tend to reduce it. It’s also good to know whether the fuel economy gauge in your car is accurate. In my experience, the gauges always make your fuel consumption look better than it really is.

I’ve made the process very simple for myself by creating an Excel spreadsheet that instantly calculates kilometres per litre and litres per 100 kilometres, with a running average for the last ten fill-ups. Now I’m making it simple for you, too, with a downloadable blank spreadsheet that has all of the formulas to make those calculations. All you have to do is reset your trip odometer at each fill-up, record the number of kilometres on the till slip—which already has the litres printed on it—and enter those two numbers on the spreadsheet.

To have your own copy of the spreadsheet, click on this link:

FuelEconomy

You should then be offered the option of opening it directly in Excel or saving it. Either option works, but if you choose to open it directly and then wish to save it—using Save As—you must be very careful to save it in the folder where you keep spreadsheets. It will not automatically opt for the My Documents folder.

After using it, if you’re not pleased with the fuel economy you see, try my 10 Unconventional Tips for Saving Petrol.

Note: FuelEconomy.xls was scanned with a fully updated version of Norton AntiVirus 2009 immediately before it was uploaded to GreenerHouse. No viruses or other security risks were found. That said, GreenerHouse promises not to take credit for your improved fuel economy if you promise not to make GreenerHouse responsible for any troubles with your computer or your spouse arising from the use of this file.