>AUTOS: Mercedes Diesel Sales Lagging

Despite fuel savings, modest extra cost and green credentials, Blutec models are slow sellers.

The Mercedes-Benz ML350 Blutec diesel touts excellent drivability and much-improved fuel mileage, yet it sells far fewer than the gasoline versions. (Photo: Mercedes-Benz
Mercedes-Benz offers a clean-diesel Bluetec version of each of its large utility vehicles, the R-Class, GL-Class and M-Class, along with a Hybrid version of the ML. But even combined, the standard gasoline versions of these vehicles are far outselling their greener counterparts that don't cost much more.

In the case of Mercedes' R-Class luxury people-mover, only about five percent in the U.S. are purchased in Bluetec form, even though the 2010 Mercedes-Benz R350 Bluetec costs just $1,500 more than the V-6 gasoline R350 (2011 prices are pending but won't change significantly).

We find that a little puzzling, as after a recent First Drive of the spruced-up 2011 Mercedes-Benz R-Class, the R350 Bluetec in particular remains one of our favorite long-distance road-trip vehicles.

The R-Class people mover, already a niche product for Mercedes, sells almost no Blutec diesel versions. With its cavernous interior and adult-size seating for six (or up to seven), the R-Class is a step above minivans for anyone who places the priority on passenger comfort. And with the diesel, it has plentiful load-stomping torque yet can return fuel economy in the mid-20s, which is quite the feat considering its more-than 5,000-pound curb weight.

No way around it, the R-Class has been a slow seller. M-B has sold around 3,000 R-Class models per year in the U.S. It sells many times more boxy GL-Class SUVs, and some months its M-Class sales have exceeded annual R-Class sales. But even for the slightly truckier (in image) GL and ML models, only about 12 percent are Bluetec diesels.

Among older M-B models, diesels have had much better resale value, so combined with the better fuel economy and drivability, we find the economics a no-brainer.

As a surprising number of shoppers still turn their noses up at diesel, Mercedes-Benz is covering all the bases; in addition to its Bluetec, the ML450 Hybrid first went on sale – or rather, on lease – late last year. The automaker is offering it only under a special lease, either at $659 per month for a 36-month lease or $549 per month for a 60-month lease.

With a 275-hp, 3.5-liter V-6 and an electric-motor system that brings output to a combined 340 horsepower, the ML450 Hybrid has roughly the same power as the gasoline V-8-powered ML550, while its EPA ratings are 21 mpg city, 24 highway. The packaging isn't any different than the standard ML; the liquid-cooled nickel-metal-hydride battery pack is stored under the rear cargo floor.

But so far, the ML450 Hybrid hasn't exactly been screaming off dealers’ lots either. The automaker has been moving ML450 Hybrids at only about 80 per month.

Back in the 1980s, more than 75 percent of Mercedes vehicles sold in the U.S. were diesels, and that was when they were dirty and had dubious drivability. In recent years, all the pro-diesel popular buzz has not materialized into sales, even when the diesels are genuinely night-and-day better than the old versions: quieter, cleaner, more powerful and more refined.

Mercedes-Benz officials explicitly told us that it's a question of demand, not supply, especially in the case of the Bluetec models, and that it would return to a higher level of diesels only if the market supported it.