This fall break I made the journey to and from Exeter, NH as I usually do, but I did it with a much shorter interval of time between drives. I drove home Sunday evening and returned to Lafayette Tuesday evening. Both trips took roughly 6 1/2 hours, but on Sunday I was alone, and on Tuesday I had four passengers. Not only was I thrilled to have company, and subsequent entertainment, I was stoked to provide transportation for those who might otherwise utilize their parents or a similarly under-utilized (in terms of capacity) mode of transportation. I thought to myself “this is why I drive an SUV” (though it is difficult to seriously call my ’06 Mercury Mariner and “SUV”).
So we loaded up the cargo space, tossed a roof storage sack on top, and were on our way. Now, my car is not very impressive with gas mileage. It breaks my heart to see how quickly the little arm drops on the fuel gauge, but I always keep track of what my MPG averages seem to be, just so I kind of know. On the way home, I was averaging over 21 MPG, which is not impressive or great by any stretch, but for a 4WD vehicle in Jersey, NYC, and Mass Pike traffic, it wasn’t bad. However, on the way back to school, I started to notice pretty quickly that the little arm was dropping rapidly in comparison to the recent identical drive. By the time we got back to Lafayette, I estimated the MPG for the trip was barely over 17. This was moderately traumatizing to me. 17?!?
So, this got me thinking. In this context- and perhaps in others- where is the sweet-spot of eco-conscious carpooling before it treks into this mileage-reductive realm I seem to have entered last night? I assume it was because with four extra people and all of their belongings (presumably cold weather apparel of the weighty variety) the little engine that could really couldn’t. I definitely felt more resistance when I tried to accelerate, and the car just generally felt a little laggy. But 21 to 17 is a fairly significant decrease. I wonder if this is true for other cars, and if so, what it means about smart carpooling?
This post illustrates that sustainability choices aren’t always as straightforward as one might think. There is a whole rather dry field called “Life Cycle Analysis” that attempts to comprehensively answer questions like whether to use recycled plastic or paper, or cloth or disposable diapers, etc (in terms of carbon footprint). The calculations can get pretty extensive when you consider the indirect effects of choices. Obviously, driving an electric car that recharges on coal-fired electricity doesnt make much sense. But it has also been argued that by using paper, we support the timber industry, which involves forests that protect water supplies and provide habitat. If not for the timber industry, the forest might otherwise be sold to developers to chop up into lots for vacation homes. Anyway, lots to think about – whatever happened to easy answers?