Happy 12th birthday to my Honda Civic! Let’s compute how much money I spent on gas.

The first and only time I bought a car was in the year 2000 when gas cost about $1.40 per gallon. A year or two earlier, gas cost about $1 per gallon, so $1.40 seemed expensive at the time. Despite how trendy SUVs had become, I opted for a small, fuel efficient Honda Civic. Twelve years and three kids later, I am still driving that same Honda Civic. It has been a great investment for many reasons. This week when I filled up the tanked for $3.83/gallon, I calculated that a fuel economy of 37 mpg. this is much better than many newer, fuel efficient cars.

I wanted to compute how lucrative a fuel efficient car has been compared to the SUVs that I passed over. So I built a spreadsheet. If you want to check out my calculations, my spreadsheet is here.

Here is what I did. I have averaged 10,000 miles per year for the past 12 years at an average of 34 mpg. I assumed that model year 2000 SUVs get 19 mpg. I also assumed that the mpg was constant over 12 years, which seems reasonable from my back of the envelope mpg estimate every time I fill up the tank. This meant that I used 24.5 gallons per month for my Civic and 43.9 gallons per month for a hypothetical SUV.  Monthly averages for fuel prices were obtained from fueleconomy.gov, and I computed the net present fuel costs assuming a 2% rate of inflation.

Buying a Civic instead of an SUV proved to be quite lucrative: My model suggests that I saved $5693 in gas in the past 12 years compared to an SUV. This is quite significant, as gas has been pretty cheap most of the 12 years and haven’t driven much.  Had I driven more, I would have saved more. If I drove 12,000 miles per year (about the national average), I would have saved $6569. If gas cost the same as it does now (a national average of $3.58) for all 12 years, I would have saved $9938 over 12 years.  I would save much more if you consider the typical lifetime of a Honda being about 250,000 miles–I’m not even halfway there yet.  The Civic cost about $15K back in 2000, which means that the gas money saved over the lifetime of the car is close to the purchase price of the car. So if you’re in the market for a car now, fuel economy is very important!

I can’t say that I really saved $5693. A report from the Texas Transportation Institute indicates that when people have more fuel efficient cars, they tend to drive more, thus negating some of their savings (I think it averages out to something like 15% more miles driven). The amount I drive is well below average, especially for someone who drives to and from work, so it’s doubtful that I would have driven much less with an SUV, but it’s something that could be added to the spreadsheet. It’s hard to overstate how much Americans love SUVs. Their market share has grown steadily since the 1970s (see the image below), and this has only recently started to erode. Gas prices have been pretty bad since 2005, and yet SUVs have only declined in popularity after the downturn in the economy. Cars have also been less popular lately–people are not buying cars or SUVs.

Here is another fuel economy fact:

Men drive way more than women. Men 35-54 drive 18,858 miles per year compared to 11,464 for women. That means that men in this age group drive 62% more than women. Similar trends occur for other age groups. There are several explanations: (a) adult women are more likely to stay at home with young children, (b) men work farther from home, (c) men like to do more joy riding.

If you’re curious, my Civic is pictured below. I hope it continues to serve me well.

My sweet ride!

The number of cards and light trucks (mostly SUVs) sold per year. SUVs have become very popular.

The monthly cost calculations are below.