Tuesday, December 6, 2011

Gas or GU?

Does it cost more to commute to work by car, or by bike?

Seems like the answer would be rather obvious. Gas is expensive and cars are inefficient and heavy--while bikes are cheap, light, and efficient. Surely, then, riding a bike much be cheaper!

But fancy energy foods like GU and Powerbars aren't cheap. One packet of GU (100 calories) costs about $1.35 at REI. How many GU packets do I need to pedal my bike to work?

Time for a spreadsheet. According to my Garmin bike computer, I burn about 1700 calories on my 34-mile ride to and from work (I ride fast, since I'm training for the CTR). That translates into 17 GU packets, for a total cost of $22.95.Yikes!

OK, but what about driving. Between my Honda Element and Honda Fit, I get about 28 miles/gallon. Therefore, I burn about 1.2 gallons of gas getting to work and back. At today's gas prices, that's about $3.95.

So, it looks like riding is WAY more expensive than driving. Even adding in the cost of wear and tear on the car, maintenance, etc., I'd have a hard time stretching $3.95 anywhere close to $22.95.

But I don't eat GU packets for breakfast--or for lunch. How about if I power my bike commute with Cheerios and skim milk (the breakfast of Cat 6 champions)? That comes out to $3.62. Much better!

Lots of college students ride their bikes to work, and they're not exactly flush with money to buy GU. When I was in college, I ate a lot of Ramen noodles. My spreadsheet reports that commuting on Ramen only costs 76 cents. Yeah, WAY cheaper than driving! Maybe I should eat more Ramen.

Now that I've got my nifty spreadsheet, I'm going to plug in some more foods. Steaks, pinto beans, etc...


  1. Silly - you are comparing expensive 'fuel' to subsidized cheap fuel and saying that the car only costs fuel - consider how much IRS will let you deduct per mile for driving and you get more toward the actual car cost.... Bicycle maintenance is way less - I quite driving over 7 years ago...

  2. Anon: Of course it's a silly post! I ride my bike to work for a number of reasons, including the facts that it's less polluting and cheaper (when including the costs of car maintenance, subsidized oil, etc.) But the truth is that "fuel costs" are about the same--which I find amusing!

  3. I disagree with anon -- fuel cost is a valid consideration. There's much more at stake than political claims that hydrocarbon fuels are subsidized. First, we can dismiss for the most part that claim, unless we want to introduce a complex and controversial calculation that assumes future costs based on worst case scenarios related to gaseous carbon byproducts. Let's stick to the subsidy we share - the roads. We wheelmen were the ones who first advocated for subsidized paved roads, so lets not throw stones at the concept of subsidy.

    Then lets dismiss the idea that a 34 mile daily round trip is practical for everybody. How many children do you have Todd? For many people, two hours with family is worth more than two hours pedaling. I've commuted that distance in far northern weather to an outdoor job, but it's not something I could sustain. I couldn't transport tools, and I couldn't keep up the between-sites requirements which I otherwise traveled in employers vehicles. My days of self-righteous commuting, or even self-satisfied commuting tended to fade no matter how desperately I tried to hang on to them.

    When my work demands changed, I could no longer rely entirely on a bicycle. I couldn't transport enough gear nor could I make it to scenes where I needed to work. I know some people in my line of work that maintain they can commute and work on bikes, but their employer makes compromises -- including having me pick up the slack and I have a car where I can roll out to an emergency 10 miles away, which is part of my work sometimes. Likewise, I couldn't show up rain drenched or sweat soaked. I've been preached to by a few younger folks who haven't put in the 10s of 1,000s of miles I have who go back to the "just change tee-shirts" sermon, but that doesn't cut it. Nor does "make society change to fit your needs" -- not unless I want to be an evangelical green, which is too close to another brand of evangelical I roundly rejected long ago.

    Now to the calories. Gadd's calcs are interesting. If one is burning calories quickly, most of the fad science about glycemic load and slow food goes out the window. I would prefer a bowl of Bear Much 10-grain cereal to Ramen noodles, but I ate a lot of apple fritters when I was a 140lb commuter burning 3000 calories on the ride and another 2,000 or 3,000 throughout the day. I could get away with more beer consumption, too.

    At first, I doubted Gadd's Garmin, but it's probably close. 50 calories per mile is an efficient burn and sounds reasonable compared to walking at 80 calories a mile, or running at 120 (based on online sources that cite lab results). Wpedia cites a source that says food energy requires 5X as input as produced because of burn losses. "Subsidized" (poor dinosaurs, paying for our greed) fuels are highly concentrated sources of energy. To get metabolized energy outputs at caloric purchase costs less than concentrated hydrocarbon costs requires low-cost metabolic calories -- Rammen noodles, oatmeal, even high-fructose sugary fountain beverages or good old beer. Good post, Gadd.

    With fuel costs figured out tackle the social costs - time lost commuting and social opportunities lost because of less convenience, inability to transport gear, clothing requirements and inclement weather -- then we can start to make bike commuting comparable in a real world situation without resulting to hell-fire-and-brimstone approaches to promote our preferred way of life. kay?

  4. Hi Anon,

    I have a family (wife, one kid), and I own a business, so time is very precious to me. That's actually one reason that I bike commute. Driving takes me an hour, riding a bit less than 2 hours. So for an extra hour/day, I get the equivalent of two hours of training! If I drive to work, and still want to ride for two hours, then I end up losing three hours of family/work time. So, commuting by bike saves me about an hour a day. Of course, I could choose to to ride or train at all, but then I'd be kind of a PITA to be around!

    I have also questioned my Garmin. But I ride at a very aggressive pace, often incorporating intervals and other speed work. My commuter is also heavy, with panniers containing my computer, clothes, etc. I don't know if it's exact or not, but it seems reasonable compared to other sources. Even with all the gear, I average about 19-22 MPH, depending on wind, traffic, and attitude.

    Not everyone can ride 34 miles/day, so my routine isn't something that everyone is capable of emulating. But I think that it's good for the environment and good for my health to ride more and drive less.

    Just for the record, I don't bike commute as much as a lot of people. I'm a wimp when it comes to darkness and crappy weather!

  5. Same anon#2 here...

    Training -- that seems to be the keyword. I noticed you like to race, which adds lots of points to the benefit side of the worth-it-or-not algorithm. I assume that's the kind of training you mean.

    For those who don't share that ambition, general cardiovascular health can be a reason to commute -- getting in some cardio "training." I've tended to resist those who call my workouts "training" but it's a semantic thing. On the "trainer" I'm not "training for the season" as some younger compadres suggest, but rather trying to live through this day, sometimes.

    All the same, yeh, that's all on the benefit side. There are byproducts of exercise indicated by high C-Reactive protein levels that can indicate increased inflammation resulting from excessive exercise. Probably choice of foods has something to do with that, but even among experts, I'm not sure the science is settled. That factor might be a contra-indication for large burns of low-quality carbs.

    "Good for the environment" is a socially popular construct, but whatever we do it's as often more a matter of "less harmful to the environment" than actually improving ecosystems around us. Even then, "environment" is a anthropocentric construct -- it refers to the world around us, rather than some ecosystem in which we're not as immersed.

    What would be good for that environment - or at least better for preserving what parts of it were there before we arrived (if we stipulate that it had some very useful directions before we wise apes started changing things around), would be to spend our days interacting with natural ecosystems - husbandry, if you will.

    All that said, I still think your carb-cost spreadsheet is a useful tool. I'd love to see it as one branch of a more complex values algorithm, even if it just helps us think in terms of money value as compared to those vague values I reference.