Jun 29 2009

Is There a Diesel in Your Future?

Posted by: Jonathan Marshall

Slow, loud and smoky, brought to you by General Motors.

That was the how Americans came to perceive a variety of ill-designed diesel cars more than two decades ago, after giving the fuel-efficient technology a try in the wake of the two oil embargoes. Diesel was a bust here in the U.S. of A.

So what is it about diesel cars today that makes them account for about half of new car sales in Western Europe?  It turns out that engineers have quietly made them clean enough to pass the tightest air regulations, while retaining their famed accelerating power (torque) and fuel efficiency.

Diesel fuel has more energy than gasoline and diesel engines tend to have higher intrinsic efficiency than spark-ignition gasoline engines. Diesel fuels can also be manufactured from vegetable oils or animal fats--even recycled restaurant grease--making biodiesel an especially attractive "green" fuel.

There's more good news: after a nasty spike last year, diesel prices are back below gasoline. According to figures from the U.S. Energy Information Administration, diesel prices in California last week averaged $2.79 a gallon versus $3.01 for gasoline, a 22 cent spread. 

This confluence of improved technology and lower fuel prices is giving a big boost to Volkswagon, maker of the diesel Jetta TDI. Sales of the diesel-engined Jetta in the United States are running far ahead of the manufacturer's projections.

The $22,000 Jetta TDI was named Green Car of the Year last November by Green Car Journal, which said the vehicle "raises the bar significantly in environmental performance with its EPA estimated 41 mpg highway fuel economy, reduced greenhouse gas emissions, and extremely low tailpipe emissions. This is all the more impressive when you consider the Jetta TDI is a clean diesel, achieving the kind of fuel efficiency offered by gasoline electric hybrids but in a more affordable way." 

Riding the diesel wave, Volkswagon recently unveiled its BlueSport roadster, with a top speed of 140 mph, 258 ft-lbs of torque, and 0-60 acceleration in less than 6 seconds. Its U.S. fuel economy is estimated at 42 mpg.

Like Volkswagon, Mazda is reportedly focusing on clean diesel engines ahead of more expensive hybrids. And Audi is launching a major marketing campaign for its new line of diesels.

The latest surveys suggest, however, that only a third of Americans would consider buying a diesel car. Maybe the Old Country still has something to teach us about new vehicle technology. 

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