A while back, a friend said:

Speaking of fossil fuels, why haven’t all automobiles gone diesel yet? Seriously, it’s better than regular gasoline and hybrid cars.

It reminded me of a conversation Krista and I had in connection with some car trouble we were having a few weeks back.

It turned out to be some fairly expensive car trouble by the time it was all done, which always starts me thinking about buying a new car. I was curious about the diesel issue, so I started looking around on the web for information. One very interesteing and informative site was the EPA’s Green Vehicle Guide.

A Google search on “diesel emmissions” led to an article on the American Lung Assicioation web site titled Diesel Exhaust and Air Pollution. This article stated that

For the same load and engine conditions, diesel engines spew out 100 times more sooty particles than gasoline engines. As a result, diesel engines account for an estimated 26 percent of the total hazardous particulate pollution (PM10) from fuel combustion sources in our air, and 66 percent of the particulate pollution from on-road sources. Diesel engines also produce nearly 20 percent of the total nitrogen oxides (NOx) in outdoor air and 26 percent of the total NOx from on-road sources. Nitrogen oxides are a major contributor to ozone production and smog.

So while a wholesale switch to diesel engines might help alleviate the issues arising from dependence on oil (foreign or otherwise), it has the potential for a dramatic negative impact on the quality of air avaialbe for us to breathe. (Those of you looking for something to do should consider applying for a grant from the Texas Environmental Research Consortium to look for a solution to this problem. Check that out here. Better hurry, though. The application window closes October 6, 2006.)

Like most problems in our world, this one is both complex and interactive. Solving the “dependence on foreign oil” problem by employing bio-diesel-fueled engines, may increase air pollution. To solve the air-pollution problem, we could employ “zero-emission” electric cars. Unfortunately, the batteries for those cars contain hazardous materials that must eventually be disposed of, and the electricity with whcih their charged must still be generated somewhere, which in most cases is done by burning fossil fules of some sort. These are “zero-emission” at the end-use, but in reality just relocate the discharge of the emissions. Even if we generate that energy with a nuclear reactor, we solve the combustion emissions problem, but then have to deal with the resulting waste that will be dangerous to human life for generations after we’re all dead.
What to do… the option with the highest potential for positive impact with the least number if undesirable consequences is simply to reduce our demand for fuel. High-efficiency technologies can do this but, as I’ve just described, can have multiple, unintended negative consequences.

So back to my car problem … The fuel economy of our 1995 Saturn SL1 is currently around 30 mpg (I’m hoping some of the work we had done will get us back around the 35 mpg we got when it was new). One of the questions I had in pondering the repair expense vs new car issue was whether buying a highly efficient new car would be to my financial advantage. So here are the numbers:

  • My commute to work is 39 miles one-way, which makes 78 miles round-trip.
  • I usually work from home one day a week, so I make this trip 4 days a week.
  • Between vacation and business travel where I’m out of town and not making this trip, I estimate that I’m driving over there 43 weeks a year.
  • So the grand total, just getting to and from work for me, is 13,416 miles.
  • At $2.80/gallon and 30 mpg, that amounts to $1,252.15 a year in fuel cost.
  • If I increased my fuel economy to 55 mpg (a just-barely possible feat with the cars currently on the market), it would drop my annual fuel cost to $683, resulting in an annual savings of $569.16.

Then I began to wonder how high gas prices would have to climb to make buying a new car a financially attractive proposition. So, assuming that I woud need an arbitrary $300 a month to make the payment on this technological transportation marvel, gas would have to cost $17.71 a gallon to pay for the new car with fuel savings.

So even while it makes environmental sense to squeeze the maximum performance from every gallon of fossil fuel, it doesn’t make financial sense to trade my 30 mpg car for a 55 mpg car. As you can tell, I’m a curious fellow and consequently became curious about the savings I could achieve by directing my attention to the other variable in this equation: the number of miles I drive.

By reducing my daily commute to 10 miles round trip, it drops my annual milage from 447.2 miles/year to 71.67 miles/year (I’m assuming that if I live that close, I’ll work in the office 5 days a week instead of 4). Without buying a new car, I can save $1,051.49 a year! That’s almost double the savings produced by upgrading the technology! Now that doesn’t necessarily mean I should move or change jobs, since, like our gas->diesel->electric->nuclear problem above, there are multiple other independent variables involved (not the least of which is that houses within 5 miles of my office typically cost 3 or 4 times the cost of our house here). I share all this to make the point that my initial focus on a technological solution (increased fuel economy) prevented me from even considering a behavorial solution (driving less) when, in fact, the behavioral change can have a much more significant impact.

Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes:

<a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>