I used to be the proud owner of a 2009 Volkswagen Jetta TDI. I still own the car, I am just not feeling proud these days. My car failed a chemistry test. TDI is a VW acronym that means diesel. In case you missed it, Volkswagen has now admitted to programming diesel cars to adjust engine operation while under dynamometer testing in order to meet emissions standards for NOx. At all other times, NOx levels exceed emission standards. I have been driving a lie. It is even more disconcerting because I purchased the car largely to feel good about myself. I paid more to lower my personal environmental footprint.
I had a couple of criteria that led me to the Jetta diesel. First, I wanted to be able to put a trailer hitch on the car. I replaced a pick-up truck several years ago with a utility trailer and wasn’t prepared to give that up. Second, most of my driving was with me alone in the car, largely to-and-from work. I wanted the best mileage I could get in an enclosed vehicle figuring that I never needed to worry about passenger comfort. I test drove the two highest mileage cars that were readily available at the time, the Jetta and the Toyota Prius. The Prius was not approved for towing and the Jetta was. Decision made.
There were a couple of minor points that also favored the Jetta. First was the innovative NOx trap technology. I spent most of my career working in catalysis. I loved the idea that inventive scientists had discovered a way to trap and react nitrogen oxides on an inorganic matrix using only fuel. It appealed to me as a catalyst chemist. Some have termed the Prius “conspicuous environmentalism”. I actually liked that the Jetta was super-efficient, but NOT conspicuous. It is identical to the gasoline Jetta with the exception of a TDI emblem on the rear. It made me feel better that my environmentalism wasn’t for show.
I purchased the Jetta knowing full well that it was a bad investment. I had done a number of analyses, even developing a nomograph that allows the calculation of potential cost savings by mileage, fuel cost and miles driven. Fuel economy would never make up for the higher sticker. I paid approximately $7,000 more for the car. That was the full difference between the base Jetta with gasoline engine and the base TDI. It was environmental performance I wanted and I paid for it. Using my nomograph, one of my former bosses sent me a teasing email stating that I only had to drive 190,000 miles to break even. Driving approximately 9,000 mile per year as I do, I don’t think I am likely to reach the 190,000 mile mark.
The Jetta exceeded my expectations. Unlike other cars that I had purchased that never reached the EPA estimated mileage, the Jetta proved to be as efficient as advertised. If I drive sanely, I get 500 miles on a tank and the pleasure of only visiting the pump once a month.
Fuel economy, comfort, performance and even the number of cup holders are observables used in the car buying decision. They are immediately verifiable. I purchased the car, in part to reduce my personal CO2 footprint. That footprint correlates directly with fuel use, something I measure every time I fill up. NOx emissions are not so easily observed. I can’t come up with a practical way that I could even measure them. I have to trust VW and the EPA to conduct the chemical testing confirming the car’s emissions fall within the acceptable range. The VW debacle draws attention to the importance of trust in our modern society and how difficult it is to verify performance. My safety in the car, in the food that I buy, the pharmaceuticals I take, the chemicals in the paint I use, the websites I visit, the appliances I use…the list truly goes on and on. Like a chain, our ability to trust any company is a matter of the weakest link. We have rules and we have laws to prevent individual weakness causing poor decisions. The unthinkable has been realized. Rules and laws will be tightened and trust will slowly be restored. I am still driving my car. It is the same fuel efficient car that I bought. I knew before I purchased the car that diesel engines generate more NOx than gasoline powered engines. I also knew that Europe had elevated fuel economy over NOx, a compromise aimed at reducing the long range threat of climate change over the more immediate concern over NOx. There is no perfect solution. I always strive to use data to inform my decisions. The data available indicates that my car may be exceeding the EPA mandated NOx emissions by up to 40 times. This still represents a significant reduction relative to the cars I have driven over my life, equal to the emissions standard set in 1977. I am not happy about it, but I am hardly pillaging the environment. The actual level is well below allowable levels for heavy trucks that drive far more than I do, creating a far larger environmental burden. The actual amount I generate in a year is far less than the NOx produced by burning a cord of wood, natural as that is.
Living more sustainably is about compromise. The NOx issue with my car is just an unthinkable compromise I didn’t see coming.
Mark Jones is Executive External Strategy and Communications Fellow at Dow Chemical since September 2011. He spent most of his career developing catalytic processes after joining Dow in 1990. He received his Ph.D. in Physical Chemistry at the University of Colorado-Boulder doing research unlikely to lead to an industrial career and totally unrelated to his current responsibilities.