On Used Cars

As I wrote earlier my new job requires that I drive to work every day. (I am working on biking to work, there is tremendous feeling of shame to drive today, Earth Day, especially since it is such a lovely day). Anyway I bought what I think is one of the most environmentally conscious vehicles out there.

No not a Toyota Prius, and I want to smack anyone who suggests a Prius is a good choice for the environment.

Consider for a moment that a Prius uses huge batteries filled with toxic chemicals that have a useful life of about four years, then all the parts that a Prius is made from have to be shipped from all over the world, its not like the thing is made from a pile of raw materials in Toyota City. The Prius has two different drive systems and a complex computer that does have a way of failing, apparently, as well as a convoluted transmission system and annoyingly grip-less tires, perfect for getting into a skid on Toronto roads in the winter.

The car I bought is a very used (300,000 km, or about 186,000 miles) 2001 VW Diesel Jetta. Being the physics major I almost was, I should point out that 300,000 km is how far light travels in a vacuum, in a single second. By contrast it took that little diesel almost ten years. So why is a diesel Jetta better for the environment than a Prius?

Well for one thing, a diesel is made from very conventional materials and parts, besides being cheaper, this means items typically do not travel nearly as far to get the vehicle built or maintained. Although admittedly the Jetta does loose to the Prius in fuel economy. On a recent drive from Toronto to Rochester and then tooling around Rochester a little and drive most of the way home (about 400km all in) I burned 21.88L or achieved 5.47L (of diesel) per 100km, by contrast according to the EPA fuel economy statistics a Prius should achieve a whopping 4.86L (of petrol) per 100km, in other words over the 300,000km my Jetta has been road worthy it burned an additional 1830L of fuel then had it been a Prius.

Of course since the Jetta is a diesel I should expect the car to be road worthy for at least another 200,000km or so, in short that Jetta should probably go on running for something in the neighbourhood of two and a half times the life span of a Prius. Building a car burns a lot of energy, 1830L of fuel equivalent? Probably a lot more, and really the energy is required to build two and a half cars!

Of course someone reading this is thinking about Ethanol as some sort of solution to all that ails the world; a solution that a diesel car cannot take advantage of. First Ethanol, at least corn Ethanol takes more energy to make than you get out at the end, in other words, corn Ethanol is not a solution to anything except low corn prices. Second Ethanol, because it takes so much energy to produce is actually worse for the environment than plain Jane petrol. Finally there is a plant derived energy source that requires little energy to produce, can be generated from plant waste, i.e. corn stalks, not just the edible corn itself, is actually edible and can be used as a lubricant, except it only runs in diesel and is called bio-diesel.

Is my little Jetta a cure for that which ails the world? Of course not, my bikes yes, not the car. But the Jetta is a step in the right direction.