German Automakers Driving a US Diesel Boom
By Chris Haak
US consumers tired of the complexity and poor acceleration performance of hybrids (not to mention an unnatural driving feel) have been flocking to diesels in the US since 2007. And why not? Modern diesel exhaust is now basically as clean as a comparable gasoline engine’s exhaust, turbodiesels can match, and often exceed, the performance of a similarly-sized gasoline engine, while typically delivering 20 to 25 percent better fuel economy.
According to Automotive News [sub], US diesel carsales were around 8,000 units per year in 2007 and 2008, before increasing twenty fold to about 160,000 in 2009. Of course, that car-only number excludes trucks, as heavy-duty pickups like the Ram HD, Silverado/Sierra HD, and Ford Super Duty all are predominately equipped with oil burners.
Funny enough, diesels aren’t stealing share from gasoline engines, but from hybrids. Diesels accounted for 2.6 percent of the US car/truck market in 2009 (up from 2.2 percent in 2008), while hybrids saw their share fall from 2.4 percent to 2.2 percent. Again, the diesel truck sales certainly help the diesel market share numbers, but the fact remains that diesels have proven increasingly popular with consumers.
Leading this onslaught of diesel cars are the German automakers Mercedes, BMW, Audi, and Volkswagen, and they’re showing no signs of slowing their advance. Audi currently sells a diesel A3 and a Q7 SUV, but plans to offer an A6 and A8 diesel as well within the next two years. Mercedes-Benz plans to show an S350 diesel at next week’s Detroit auto show that will get 35 miles per gallon on the highway, which is an impressive figure for a large, powerful sedan. Mercedes-Benz already offers diesels in the M, GL, and R-Class SUVs. BMW, for its part, offers a diesel in the 3 Series and X5, and is strongly considering a 5 Series diesel as well.
Though modern diesels can put up similar performance numbers to their gasoline-engined counterparts, the driving experience is something a bit different and unfamiliar. After a brief hint of turbo lag, they take off with a turbine-like smooth rush of power, with no audible clatter. Shift points occur at very low RPMs, as the engines run out of breath rather quickly in the higher revs. Off-the-line acceleration is brisk, and the cars and SUVs tend to be very ambivalent toward hills or full loads of passengers, but passing power is not generally very impressive.
Apparently, diesels are selling themselves, as luxury buyers are less concerned about the price premium required (typically between $3,000 and $5,500), and they’re usually sold almost as soon as they get to the dealer and do not spend time sitting in inventory. One possible exception is that BMW is offsetting its diesel premium by offering buyers a $4,500 rebate on the 335d and X5 xDrive35d.
With the sudden interest in compression-ignition cars, plus the continued preference for diesels in the HD truck market, it makes one wonder if GM and Ford might dust off their light-duty diesel that had been shelved during the industry’s dark days. GM’s light-duty Duramax was to displace 4.5 liters and produce about 300 horsepower and 450 pound-feet of torque, while fitting into engine bays designed for a small block V8. With CAFE requirements rising over the next decade, it’s hard to imagine a scenario in which diesels won’t play a major role in reducing the US fleet’s fuel consumption over that time period.