From a Rumble to a Gentle Purr

It began with a rumble, in the manner of a person awakening from a deep sleep with a heavy cough. I did not like this.

I'd lately grown accustomed to smooth diesel engines -- advanced common-rail versions that ran so quietly it was hard to tell if they were diesels.

So, this greeting from the 2.8-liter turbo-diesel engine in the 2005 Jeep Liberty Sport CRD (Common Rail Diesel) was disconcerting. Harrumph, rumble, rumble, clatter-cough! What was that?

I felt betrayed. I'd long been a vociferous advocate of new diesel technology -- clean-burning, fuel-efficient diesels -- engines absent the noises, odors, emissions and operational difficulties that stigmatized diesels of old.

I had driven many vehicles with these new engines, especially the super-efficient common-rail diesels that deliver their fuel to combustion chambers precisely under uniform pressure, thus assuring a more complete burn of the air-fuel mixture, yielding more power with a minimum fuel penalty and fewer particulate emissions.

Harrumph, rumble, rumble, clatter-cough! I was dismayed. How could this be? Maybe it was the frigid night air. The temperature had fallen to 26 degrees Fahrenheit. Wet things froze. Maybe the engine was reacting to the cold. Older diesel engines normally did that sort of thing.

But this was a new engine, a much-revised version of a four-cylinder diesel used by DaimlerChrysler AG in a number of its European-market products. Allow me to digress:

The modern automotive industry is a melange of global relationships, of which the Liberty Sport CRD's turbo-diesel -- the first such engine installed in a mid-size SUV sold in the United States -- is a product.

The engine is made by Italy's VM Motori, a company partly owned by Detroit Diesel, which is a wholly owned subsidiary of Germany's DaimlerChrysler AG.

DaimlerChrysler, formerly Daimler-Benz AG, owns what was once America's Chrysler Corp., which now exists as the Chrysler Group -- a divisional entity within the DaimlerChrysler empire.

The Chrysler Group produces and sells all Jeep vehicles, including the Liberty Sport CRD.

The diesel-powered Liberty represents a risky marketing step for DaimlerChrysler and its Chrysler Group. Diesel cars and trucks are all the rage in Europe, accounting for nearly 50 percent of new vehicles sold in that market, where gasoline can cost as much as the U.S. equivalent of $5 a gallon.

Diesel-powered vehicles generally get 25 to 30 percent better fuel economy than gasoline models. That reality, when coupled with favorable European pricing for diesel fuel, helps explain the overseas popularity of diesel engines.

But in the United States, diesels long have labored under the reputation of being noisy polluters, an increasingly undeserved rap, thanks to new technological developments. That is what DaimlerChrysler wants to prove with its Liberty Sport CRD. The idea is to offer a mid-size sport-utility vehicle that gets the fuel economy of a four-cylinder sedan while providing the acceleration of a strong V-6 and the torque and pulling power of a workhorse V-8.

I like that idea. I again keyed the Liberty Sport CRD's ignition. There was a slight hint of a rumble, but the sound quickly turned into a pleasant burble. Cars and trucks, it seems, are a lot like people. First impressions, good or bad, can be misleading. I was misled by the Liberty Sport CRD's boisterous introduction.

Barely 15 miles into my nocturnal journey into Virginia's Shenandoah Valley, I had forgotten that the SUV was powered by a diesel, or that the diesel was a small four-cylinder job. It really did feel like a powerful V-8. It accelerated without the slightest hesitation, changing lanes with absolute confidence; and that steady burble on a cold early winter's night gave me feelings of warmth and comfort.

I drove the Liberty Sport CRD much longer than I had planned to that night. I awakened the next day and chose it over several other vehicles in my driveway for a trek into the District, where it proved quite nimble in tight traffic and where it also fit nicely into parking spaces for mid-size sedans.

My disappointment turned to celebration -- and relief. The Liberty Sport CRD works pretty much the way the people at DaimlerChrysler hoped it would work; and that is a good thing for the future of SUVs and other trucks in the U.S. market.