By LAWRENCE ULRICH
Published: October 15, 2006, New York Times

TAKE it from someone who spent a childhood in the backseat of diesel-powered cars: they stunk.

It wasn’t just the noxious spew from the tailpipe or the kerosene odor you endured while filling up next to towering 18-wheelers. The engines clattered and shook, or they refused to start at all on frigid Michigan mornings. They even caused cancer: several studies found the sooty exhaust to be a carcinogen, and it was linked to asthma, heart attacks and premature deaths.

My only fond diesel memory was how my penny-pinching father coaxed 300,000 miles from his oil-burning Mercedes-Benz cars and International Harvester trucks, which invariably outlived their rusting bodies.

So when I say the new Mercedes E320 Bluetec is one impressive machine, it is not a judgment colored by nostalgia. Swift, quiet and odor-free, this is definitely not my daddy’s diesel. Indeed, the Bluetec probably strikes the best combination of space, performance and efficiency on the road.

You associate 38 miles a gallon with squirrel-driven subcompacts, not a powerful midsize luxury sedan. But that is the mileage the Mercedes test car delivered in 250 miles of highway cruising. The Bluetec also posted a thrifty 28 m.p.g. in the city. Both numbers exceeded the car’s federal rating of 37 on the highway, 27 in town.

With its sizable 21.1-gallon tank, travel range becomes a selling point: the Bluetec can cover a remarkable 700-plus highway miles on a tank, or enough to travel from New York to Indianapolis (or from Los Angeles to Salt Lake City). Such all-day range saves time as well as money. Based on the 32 m.p.g. that my test car returned over all, an owner who drives 15,000 miles a year will pull over for fuel just twice a month. More...