Diesel engines are 25 to 30 percent more efficient than comparably sized gasoline engines, and, unlike hybrids, they don’t require battery packs that can add hundreds of pounds to the weight of the vehicle. Weight is the enemy of fuel economy, and that means that the batteries that provide brief spurts of electric power in hybrids are dead weight most of the time.
Even so, the Jetta wagon with the 2.0-liter diesel TDI (turbocharged direct injection) engine still falls short of most hybrids in fuel economy. The EPA ratings for the Jetta diesel are 30/42 mpg city/highway. This compares well to the gas engines available in the Jetta: 24/34 mpg for the 2.0-liter gas four-cylinder with manual transmission and 23/33 mpg for the 2.5-liter with manual, but a Toyota Prius has EPA ratings of 51/48 mpg and a Civic Hybrid is rated at 44/44 mpg.
The Jetta diesel comes closer to other hybrids like the Hyundai Sonata Hybrid with EPA ratings of 35/40 mpg and the Toyota Camry Hybrid’s ratings are 43/39 mpg, and both lose some trunk space to batteries (more so in the Sonata, which lacks a folding rear seatback). There are no such space compromises in the Jetta TDI wagon, which has the same cargo capacity as the gas model and no extra weight to lug around.
Diesels have never been as popular in the U.S. as they are in Europe, though persistently high gas prices are steering more buyers to diesel cars such as the Jetta TDI.
See if your question has already been asked and answered
Your question has been successfully submitted to Ask.cars.com. It will now be reviewed by our editors and we'll answer it soon if we think it's a useful question. You will be notified via e-mail when the answer is posted. Ask.cars.com tackles your questions about new cars and the car-buying process. Unfortunately we can't answer questions regarding:
Have our experts answer any of your questions about new cars.
Don't worry — we won't publish your last name or email.