Hybrid or diesel?
For car buyers seeking the highest possible fuel economy, this is one of the most basic questions that must be asked. Both powertrains offer higher mpg ratings and fuel-tank ranges than conventional gasoline engines. Of course, both also offer different driving experiences.
Volkswagen hasn't been shy about advertising the fuel-economy promises of the turbodiesel engine available in its Jetta compact sedan, and recently, I had the chance to put those promises to the test when a 2009 Jetta TDI showed up at my door. My friend John and I were heading east for a wedding--a nice little jaunt from Chicago to Detroit and back would give me a chance to see how realistic the Volkswagen's EPA ratings of 29 mpg city and 40 mpg highway are. It was also a chance to see just how far one tank of diesel could be stretched--could the entire round trip be made on one tank?
This experiment would be performed under real-world driving conditions--no hypermiling here. We're Americans, darn it, and that meant we weren't going to forfeit our right to air conditioning. Nor would we crawl along in the slow lane at 55 miles per hour--Michigan has 70 mph speed limits on rural interstates, and we were going to take full advantage. Finally, the Jetta would be carrying a load--a weekend's worth of luggage for two people.
Powered by a 2.0-liter turbodiesel 4-cylinder that makes 140 horsepower, the Jetta TDI can be had with either a 6-speed automatic or a 6-speed direct-shift gearbox automatic transmission.
The TDI tester arrived with a base price of $22,270. For that price, buyers get standard features such as cruise control, heated front seats, a 6-disc CD changer with MP3 capability, satellite radio, a 60/40 split-folding rear seat, and heated power sideview mirrors, among other things. Available safety features include ABS, an antiskid system, traction control, front side airbags, and curtain side airbags.
Options included a $1,990 navigation system, the $1,100 DSG automatic transmission, a power sunroof ($1,000), 17-inch wheels ($450), a rear spoiler ($329), and rubber floor mats plus trunk liner ($199). With options and the $700 destination charge, the total price as-tested was $28,038.
Our trip started around 11 a.m. CST on Friday, with nice late-summer Midwestern weather promising us mostly sunny skies for our drive and a full tank of diesel fuel that was pumped at a Mobil station at Sheridan and Broadway on Chicago's North Side. A decade ago, John and I used to make the Chicago-to-Detroit drive all the time as college freshman. We used to pass the time by talking about cars, sports, and girls. Ten years later, we found ourselves discussing the same topics--apparently, not much has changed. Armed with cell phones and iPods, we were off.
As we made our way across Chicago, the torquey turbodiesel had no trouble keeping up with traffic, although the direct-shift gearbox occasionally displayed some wonky behavior, including an unusually slow throttle response that made merging into busy traffic into a bit of an exercise in advance planning. Another DSG quirk is its habit of engine braking while coasting at slower speeds. In a true manual, this would feel natural, but in an automatic, it takes some getting used to.
Our first speed bump came in northwest Indiana--road construction on I-90 had slowed traffic to a crawl. Crawling along in bumper-to-bumper traffic sure wasn't going to help the old fuel-economy average. Still, the needle on the fuel gauge stayed on the full mark until almost 92 miles into the trip.