Of minivans and CO2

Image source: Smithsonian Magazine; allpar.com

The minivan was the brain child of Lee Iacocca and in 1983 was mass produced. It was widely successful; a product nobody knew they needed. And it saved Chrysler from bankruptcy; the rest is, as they say, history. My first introduction to the minivan was a second-hand 1990 Toyota Previa Alltrac. My ownership of that minivan was a direct result of having twins a year and a half after my first son was born; the station wagon was just not big enough anymore. We didn’t pay much attention to gas mileage or CO2 emissions; our priority was hauling the three little guys around. As you can imagine, three kids in diapers and many road trips to see family took a toll on the vehicle. After five years the car ran just fine, but the inside, well … let’s just say that with the windows up and the heat on it smelled like something had crawled under the back seat and died. Plus, it didn’t have any airbags, a safety feature for which I was willing to trade up. Therefore, we were on to minivan number two – a brand new 1998 Toyota Sienna. By then the kids were in elementary school, which meant many more road trips, but, unfortunately, the van had several unintended physical relationships with other cars. After seven years of service, three trips to the body shop and the tendency to crab sideways while going down the highway; it was time for minivan number three.

Image source: Wikimedia Commons, Public Domain [1990 Totoya Previa; 1998 Toyota Sienna; 2005 Toyota Sienna]

By that time SUV’s were popular and minivans had developed a reputation as the “soccer mom” vehicle. Plus, my wife really didn’t like driving around in increasingly larger and larger vehicles. But gas prices were going up and the new second generation 2005 Sienna got much better gas mileage than those clunky heavy SUV’s which were just getting over that tendency roll over. Again, the minivan proved its worth and served us well for almost 10 years. Now it is relegated to that suburban curse known as the ‘spare car for the kids.’ Back when the kids were in diapers and rolling around in the first van, we were looking for a house in a town with a good school system and we never thought about how they would get to their first summer jobs. Selecting a town with almost no public transportation leads to the ‘curse,’ too many cars. Anyway, that 2005 minivan a good runner that cost very little to maintain and insure. It comes in handy when the twins are home on vacation and for summer job transportation. Not to mention the fall and spring college runs.

But no one in the family likes to drive the curse-mobile – it’s too beat up, hard to park, uses too much gas and, finally, it’s a minivan! What is the reasonable thing to do? 1) Tough noogies, it runs great, get over it! 2) Sell the house and move to a neighborhood with public transportation or 3) Replace it?

Selling the house is off the table until after the boomeranging from college is complete, plus we kind of like the place after spending 20 odd years getting it ‘just right.’ What if I replace it with something my family will enjoy driving and is more environmentally friendly?

Vehicle transportation in this country accounted for approximately 32% of all CO2 and 27% of greenhouse gases in 2013. As an architect shouldn’t my decision work toward reducing these numbers? Where to start when searching for an environmentally friendly alternative? The easiest part is gas mileage because all car manufactures publish these numbers. The curse-mobile sees around 19 mpg in daily driving. Replacing it with something that improves on mileage is a positive: save gas = less pollution, right? Or is it? One assumes a car made in 2015 would produce less CO2 than a car made in 2005 on a per mile basis. But, this all depends on the model, engine size and type, style of driving, etc. Additionally, we need to consider offsetting the carbon footprint of the manufacturing process.

I started with the carbon footprint of my Sienna. By using carbonfootprint.com, I discovered my car has contributed 66.88 metric tons of CO2 in the time I have owned it (given its mileage).

I looked at the 2013 Subaru model I am considering (unfortunately the non-hybrid version was not made until 2014) and discovered it gets 35.66 metric tons for the same mileage. I am assuming a 2015 hybrid model will perform better, but the online calculator only provides calculations through the 2013 models. My new car will likely produce less than half the CO2 per mile than my current minivan does. Interestingly, my 2006 Prius is currently at 23.3 metric tons, which is almost three times better than the curse-mobile on similar mileage! And while I visited that website, I checked the calculations on an alternate scenario; what if I had purchased a Ford Explore back in 2005? That car has contributed 82.62 meter tons of CO2; glad I stuck with the minivan.

As some of you may know, cars in many parts of Europe are taxed on how much CO2 they produce, which means it is easy to obtain metrics on European made cars. Here in the land of the free to pollute, this is not so. Clearly a carbon tax on vehicles in this country would highlight this issue for consumers in the most effective way, in their wallets.

But what about that embedded energy in the manufacturing process? How quickly can a car generating less pollution offset the energy to produce the old one versus the new one? This is difficult to determine on a model-by-model basis, even in Europe. Some very basic information is available online regarding manufactures as a whole and a handful of specific cars, but even those numbers are not specific. As one can imagine, the smaller and cheaper the car = the smaller the carbon footprint because there is just less stuff in it. Expensive cars with low mileage are more than likely the worst offenders. While doing research for a previous post about replacing appliances, I discovered a “10 year” rule-of-thumb, which assumed that appliance replacement was okay after 10 years, relative to embedded energy in small consumer products. Needless to say, cars are much more complex and bigger than a microwave or a refrigerator.  That said, I think it is safe to assume that car manufactures are producing cars more efficiently today than in the not too distant past. Also, don’t forget, whether the car is manufactured in this country or overseas, which has an impact due to transportation costs. Running a car for as long as possible makes sense, unless the original car is really dirty and the replacement is a lot better. Keeping my Prius for as long as possible is a no brainer, whereas keeping the minivan is still a bit of a dilemma. Unfortunately I think it will be quite some time, if ever, before a consumer will have access to embedded energy costs on specific cars.

In the final analysis, do I choose what is best for the planet or what makes sense for my family? At this point, I can only look at the environmental impact of my choice from a post-production side of the equation. My prospective new car of choice will use two thirds the gas and produce less than half the CO2 of my current minivan. Given that my old car still runs I can assume that it will move down the automotive food chain and be driven for a year or two by a new owner until it is ultimately recycled, thus extending the amortization of the embedded energy a little while longer.

While the U.S. is behind Europe in carbon tax and consumer ability to understand the impact of carbon emissions on products (like automobiles), I believe the U.S. will adapt someday. Interestingly, the French government recently stated they are considering banning diesel engines due to nitrogen oxides levels, which have been connected to health issues particularly in urban environments. The French, along with many other countries, are pushing EV’s as part of the solution to these high pollution levels. Additionally, Toyota and Mercedes are bringing fuel cell vehicles to the market as yet other alternatives to the internal combustion engine – the times they are a-changin’.

So, the next time, or the first time, you are considering a car purchase (new or used), do some research and understand what is the exact impact of that choice on the planet. Even check out your current vehicle; the answers and alternatives may surprise you.