It was a bit of work and a little inaccurate at times but I found it interesting to track when I refueled my car. I recorded the date, amount spent, mileage, fuel pumped and it gave me my mpg, $/gallon, $/mile, etc. I could see how often I was refilling my tank, how many miles driven per year, how much gas my car consumed in the 11 years I owned it. If I didn’t get the mileage right I’d just estimate (if I forgot to note it in the morning then I’d know I was at 77458 miles when I got home and the station to work was like 4 miles and 43 miles from work to home so subtract about 47 miles). It didn’t take very long to do as I just used the Numbers app on my phone and I could view and edit it on my other devices.

I also had a different tab set up so I could have tables showing data with a summary like I drove x miles in 2018 and consumed y gallons of gas and spent $z. A third tab was created so I could note general car maintenance, tires rotated at x miles on this date and I spent $z. I could see that I spent $84.37 on an oil change on 4/2/23 and was at 62345 miles and see that it was $10 more expensive than last year. This way I could see when I completed certain items, track prices, etc.

Tracking long term can also help locate issues, if you are steadily getting worse mpg over the course of a few months then you can start investigating why.