Breaking down my gasoline consumption

With gas prices at their current levels people are hurting at the pump and even my 2.5 mile commute adds up. I usually go home for lunch so I’m driving 10 miles a day. Compared to the 50 miles I was doing one year ago I should be grateful my gas bill is as low as it is. The savings I’ve seen with a shorter commute aren’t quite as large as you’d think. The increased price of gas and lower mileage from city driving has doubled my cost per mile.

Gas prices have gone up considerably; here’s my data I’m collected over the past 2.5 years:
Price of Gas

Higher prices mean it costs more to drive a mile, no question there. Here’s my mileage over that same time period for my 2005 Toyota Tacoma 4 cylinder automatic:

When I started at the County last August two things happened: a tank of gas started lasting longer and my mileage plummeted. The short trip to and from work means my engine is operating at a less efficient temperature for a larger proportion of my commute. Coupled with stopping and idling at traffic lights I saw a 7-8 mpg decrease, that’s a very significant ~30% drop in mileage. My historic cost per mile looks like this:
Cost per mile

The double whammy of increased prices and lower mileage hurts. With my current cost per mile it costs me $2.20 to drive to work everyday. Doesn’t seem like much, but that adds up to about $550 per year. That’s just to get to work, that doesn’t include driving anywhere fun.

I’m going to go through a series of post analyzing my energy costs and figuring out ways to reduce them. What’s your daily commute cost you? Simple formula to calculate it:

Commute cost = (price of gas / MPG) * miles

7 Replies to “Breaking down my gasoline consumption”

  1. I have a friend named Lisa who rides her bike to work 15 miles (both ways) in hilly San Diego. Surely a 2.5 mile bike ride is do-able. I’m considering it for the county job next year.

  2. Despite higher gas prices and lower mpg, didn’t you still cut your gas spending in half?

    If you were doing roughly 25 mpg before, at 50 miles a day, and at roughly $2.50 a gallon, that’s about $5 a day in gas. You’ve cut your gas expenditures by over 50% by changing jobs, which is somewhere in the neighborhood of over $500 a year! All rough estimates of course, but that seems like the most important thing.

  3. I’m just nitpicking. Just comparing year to year figures, I was just surprised to find I’m paying twice as much per mile. I’m being super attentive on my current tank to see if I can increase mileage with better coasting and predictive driving. My next post is going to explore alternatives like biking.

  4. Interesting and it somewhat makes sense with gas rising as much as it has. I’ve been seriously considering getting a scooter to make my ride into the office. I really want a yellow or blue vespa and I know i’d look like a large soft/gay man… but that’s besides the point.

    When I worked in Pasadena the round trip was 41 miles. Now I’m only 7 miles from the office. It sure was was nice to have a 0 mile commute for that year and a half period of time. With the current price of gas if I were still making that Pasadena commute I’d probably end up hurting people or having to find a closer job.

    One question, you have mileage and gas data back to 8/1/05 is that accurate data (meaning have you really been keeping track of both) or are they averages? Either way it makes for an interesting graph to look at.

  5. FYI: After the last comment I posted, WP thew me to a 404 error page. I’d email you this but I don’t have your email address, feel free to delete this comment after.

  6. I was looking at scooters too. I think it would be awesome, but someone shot down that idea.

    I bought my truck in August 2005 and decided as a long term project to track my mileage in a spreadsheet with fill up date, price per gallon, total gallons and miles traveled. I used an averaged line of best fit on the graphs to help smooth things out over the ~60 data points. Been doing the same on Sarah’s RSX for a while too.

    The spreadsheet allows for some interesting analysis like my last tank lasted almost 5 weeks, but was my most expensive tank ever.

    The cycles in the price of gas is really interesting. The time between bottoms got shorter while the bottom kept rising. Going off the past 2 years I’d expect a peak in June and then a decline to about $3.40 in the Fall.

  7. Scooters. The guy I am moving in with has an old 60’s vespa. It’s nice, but lots of work. The new ones are nice too. I like the Yamahas, thanks to the many memories.

    I recommend riding your bike to work. It’s way nicer. And you can get them for cheap at garage sales. You may look foolish, but the money you save you can use at Tiffany’s for your wifey.

    If not a bike, go Moped. They get sick nast gas mileage.

    Of course, I work on a plane. Go Figure.

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