Archiv für September 2007

Cutting Carbon VI

September 19, 2007 - Markus Hoenicka
Now that my electrical power is generated without carbon dioxide emissions, there is one last source of greenhouse gases that I can do something about: my car. I commute almost every weekend to see my kids, and unfortunately the only reasonable way to get there is to go by car.

The carbon dioxide emissions of a car are directly linked to its fuel consumption. I should probably explain two terms here. In continental Europe, the gas consumption is expressed as liters of fuel per 100km. That is, a fuel-efficient car consumes less fuel to get you 100km from here. In the US, and afaik in Great Britain as well, you determine the mileage, that is the distance that you can travel with a gallon of fuel. Thus a fuel-efficient car has a higher mileage.

There have been a few serious attempts by the car industry to build fuel-efficient cars. One of them is a nice example of how not to do it. The Volkswagen company used to build a small car called the Lupo. In 1999 the Lupo 3L hit the market. "3L" doesn't denote the engine size here (which was 1.2 liter, by the way), but the fuel consumption per 100km. The 3 cylinder turbo diesel engine thus had a US mileage of 78. This translates to a carbon dioxide emission of 81g per kilometer.

This was indeed a technical feat, but the car didn't exactly sell well:

- it was very small. You could use either four seats and essentially have no trunk, or you'd use two seats and fold down the back seat to create a trunk large enough to hold a few shopping bags.
- it was tricky to drive at times as the car was too light when occupied by a single person. Early models had to be retrofitted with lead weights in the rear bumper to put enough weight on the rear axle.
- it was butt ugly, as if it had written "don't buy me" across the hood.

Technically this was the car that the Smart should have been, but the Volkswagen managers apparently tried to sell it only to those who'd otherwise be eco-friendly enough to walk by foot. In any case, the Lupo 3L was discontinued in 2004 after merely 27000 units were sold. At around the same time, Volkswagen introduced the luxury sedan Phaeton (the top model sporting a 6 liter engine that consumes 14,5 liter gas per 100km / 17 miles per gallon, releasing 348g carbon dioxide per kilometer) and the luxury SUV Touareg (top model: same engine, using 15,7 liter per 100km / 15.5 miles per gallon, releasing 382g carbon dioxide per kilometer). Both of them were considered a success, and especially the latter sold well. So much about us fighting the climate change.

My Ford Mondeo station wagon was about 10 years old and due for a replacement anyway. Not that it was broken down, but the corrosion got noticeable and a lot of minor things like the shocks and the muffler would eventually have to be replaced. I went shopping for a preowned car that fulfilled these requirements:

- about 2-3 years old with no more than about 30000km (approx. 19000 miles)
- large enough to transport a bicycle without hassles
- Euro 4 or better emission standard
- lowest fuel consumption / highest mileage of its class

It was pretty clear from the start that my new car would be quite a bit smaller than the Mondeo, and that I'd have to switch to a diesel engine to get the lowest fuel consumption possible. It was also clear that only a station wagon would be suitable for my purposes. There were a few cars to consider:

- Opel Astra
- Renault Laguna
- Ford Focus
- Skoda Octavia

And the winner is... disclosed in a future post.