This is the third and (hopefully) final post about my recent car crash and the financial aftermath.
After shopping around, we narrowed the field of contenders to just Volkswagens — either a Golf or a Jetta TDI.
The Jetta TDI was very fun to drive, especially the automatic. I usually drive a manual transmission, but these days, the automatic transmissions get just as good (and sometimes better!) gas mileage. And the Jetta manual has six gears. That’s a lotta shifting. I mean, it’s not like it’s a semi — it’s just a sedan. Why on earth, does it need so many gears?
I prefer the Golf styling. The Jetta is a garden-variety sedan. I love being able to haul stuff around, so the Golf’s hatchback makes more sense for me. The regular gas engine Golf is plenty fun to drive. The Golf TDI version is currently only available in the two-door model, which made it a non-starter for my three-person family.
TDI: Turbocharged Diesel Injection = Fahrvergnügen
Fahrvergnügen roughly translates to “driving pleasure,” and the TDI has it in spades. Not only is the engine plenty peppy, but it gets 47 mpg* on the highway. Wow! Toyota’s Prius is only rated at 55 mpg. Who knew that a diesel engine could be so efficient?
The government is currently giving rebates for fuel efficient cars, including hybrids and TDI’s. The rebate on a Jetta TDI is $1300, which about pays for the cost delta between a base Jetta and the TDI.
Our problem was that we preferred the Golf over the base Jetta. And the Jetta TDI was $4,300 more than the Golf. After Uncle Sam’s rebate, the Jetta was still $3,000 more. Could we justify the Jetta on the basis of fuel cost savings? Here’s the math.
Gas vs. Diesel
I drive 15,000 miles a year, mostly on the highway. Using the government’s estimates of 32 mpg for the Golf and 47 for the Jetta TDI, I’d use 469 gallons of gas vs. 319 gallons of diesel.
Diesel, however, costs more. In Massachusetts, I buy regular gas for $2.50/gal and diesel is about $2.70. So to drive my 15,000 miles, I’d spend $1172 on gas or $861 on diesel, for a savings of $311/year. It would take almost ten years to cover the extra $3,000 for the car. I do tend to own a car for ten years, or more. It would probably pay for itself in the end, but did I want to put in the extra money up front? You never know… ahem… when you might get rear-ended by a 17-year old driver who just wasn’t paying attention.
Is it greener?
Here’s where it gets a bit curiousier. The government’s giving rebates for super fuel efficient cars, presumably because they are more earth-friendly, right? However, you gotta remember that diesel is different than gas. Both are hydrocarbons, but the average length of the carbon chain is longer in diesel than in gasoline. Diesel is denser than gasoline (0.85 kg/l vs gas’ 0.72 kg/l) and when burned, diesel produces more CO2 than does gasoline (10.1 kg/gal vs. 8.8 kg/gal).
If I drive 15,000 miles on a Golf with a gas engine, I use 469 gallons of gas, spend $1172, and create 4,127 kg of CO2.
If I drive 15,000 miles on the Jetta TDI, I use 319 gallons of diesel, spend $861, and create 3,222 kg of CO2.
The diesel reduces total CO2 production by 22%.
Over the life of the car, 150,000 miles, the diesel car would prevent the creation of 9050 lbs of CO2. Put another way, Uncle Sam’s rebate of $1,300 is 14.9 cents per kg CO2 avoided. I wonder how that compares to the other payments made in the carbon cap and trade?
The better way to go green
If your primary consideration in shopping for a new car is the environment, then the best purchase is…well… none. If you can figure out how to get by without a car, you (and the earth) are much better off. While this can work in the city, I know of few suburbs that have sufficient local transportation.
The second greenest choice would be a used car. A new car requires tremendous inputs of raw materials and energy. On my new Golf, the transmission was made in Japan, the engine in Mexico, final assembly was in Germany, and then it was shipped to Boston, where I purchased it. The energy required for shipping all those parts around the world has ruined whatever good energy karma I might have had going for me.
* your mileage may vary.
Related posts:
Image credit: rajeshvj at Flickr
Disclosure: No positions in any companies mentioned.
Carnivals: This post was included in the Money Hacks Carnival #97 – End Of 2009 Edition hosted at the Canadian Finance Blog.
Science and Money Feed
Mombian » Blog Archive » “She Got Me Pregnant”: Episode 94
on Dec 17th, 2009
@ 2:45 pm:
[...] “green” isn’t always as easy as it seems. (Helen also goes into more detail over at her place about our car [...]
Kaushik Kumar
on Dec 26th, 2009
@ 8:18 pm:
Nice article. I was researching around for my next car, and this was the most scientific article on the choice between the various emissions type.