The Value of Going Green in a 15 Year Old Car

Not my actual car...

I decided to do a little experiment (of course) this summer to see what my car’s gas milage was like and whether or not I could coax some extra MPG’s out of my car. I drive a 1996 Subaru Outback, the model from Hell that requires premium gas and is apparently rated for 29 MPG. I logged all my travels and ran the numbers through Google Spreadsheets (probably the first time keeping something readily accessible in the cloud has been of great convenience to me). My methadology was pretty straightforward, and basic hypermiling creed.

    Smooth driving.
    Gentle braking and accelerating. (traffic permitting)
    Avoid exceeding 70 MPH.

My driving was mostly on highways and main roads (e.x. 287 and Rt. 10) so I should have been leaning towards the high-end of my gas milage.

Date Miles Gallons MPG Notes
6/12/10 195.5 8.15 23.99 Home to TCNJ
6/18/10 153.4 6.04 25.42 Michelle’s House, TCNJ
6/20/10 172.5 6.34 27.2 Autumn’s House & Home, TCNJ
6/26/10 156.4 6.47 24.17 To/From Home
7/5/10 257.7 8.73 29.53 <– Weird…
7/18/10 237.7 9.54 24.92 To/From Home + Christine’s, TCNJ
7/25/10 230 8.73 26.36 To/From Home + Michelle’s, TCNJ
Totals: 1,403.20 53.99 25.99
Worst Case: 1,403.20 58.47 24
Saved: 4.48 $2.80/gal $13 Saved
Annual: $75
Time Lost: Assuming 5-10 min. per trip 110 minutes

The results are… well, underwhelming. Although I hit 29 MPG once, it never happened again in any of my driving. If i drove conservatively over the course of a year, I would save about $75 (compared to the 24 MPG average I got last summer). This is all assuming that weather plays no factor, of course. In the winter time, my MPG is a little lower even though I’m not using things like A/C. I would save a little less than my own body weight in CO2 emissions.
Now this isn’t ‘extreme’ hypermiling by any stretch of the imagination. These are just simple things anyone can do. The truly obsessed take off roof racks, cover up wheel wells, and aerodynamically streamline their cars. But the point remains: I didn’t save that much money over the course of 2 months. People pay more for monthly cell phone bills than I would save in a year.

So where does that leave me? Well, for starters, I’m probably just going to drive however I feel like driving. A single digit improvement in MPG is so statistically insignificant in a world chock full of traffic problems that it’s not worth worrying about. You have better things to pay attention to besides your speedometer.

For anyone else, unless your car is capable of hitting 30+ MPG, or only gets less than 2o, it’s probably more of a headache than it’s worth. If your driving is terribly wasteful to begin with… then maybe there’s room for significant improvement.

Left lane, welcome back to my life.

2 Responses to The Value of Going Green in a 15 Year Old Car

  1. Now I drive a 2003 Jetta which is supposed to get 24mpg or something like that. I usually get between 28 and 34.

    I haven’t done a huge study on it, but basically I can get about 400 miles out of a tank of gas, or I can get 200. It’s a fairly huge difference, so I tend to drive more conservatively, and hit neutral as much as I can. P: Too bad my model is a decidedly not-aerodynamic model to begin with!

  2. Haha, that’s cool. At least you know your driving style will give you some kind of positive return.

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