For most of its existence, the diesel engine has been the polar opposite of a high performance powertrain technology. Sure, Uncle Rudolf’s Sparkless Wonders have qualified on pole for the Indianapolis 500 (60 years ago with Freddie Agabashian at the wheel of the Cummins Diesel Special) and won a boatload of big league sports car races in the back of Audi and Peugeot prototypes, and 3/4- and 1-ton pickups with upgrades from tuners like Banks Power are able to make insane power and torque figures and cover the quarter-mile much faster than anything weighing four tons should. But generally speaking, diesel power has been much closer to plow horse than thoroughbred.
However, some companies have tried to change that, and not just out on the track. And one of the most prominent examples of an OEM attempting to give diesel power a sporty image is the Mercedes-Benz C30 CDI AMG. Make the jump to learn the story behind AMG’s first – and thus far only – diesel.
The story really begins in the mid-1970s, when Mercedes-Benz built the C111-III research vehicle. Unlike the first two variants of the C111, which were powered by gas-burning rotary engines, the C111-III used an experimental turbocharged version of the company’s OM617 3.0L inline-five diesel. Tuned to produce 230hp, the engine propelled the ultra-streamlined C111-III to multiple diesel and outright speed records before being de-tuned and civilized for street use and making its production debut in the North America-exclusive 1978 300SD Turbodiesel.
Alas, Mercedes shelved the idea of a diesel sports car after it retired the C111-III, but as the 20th century drew to a close, the idea resurfaced. However, instead of creating a dedicated mid-engine sports car platform, Mercedes-Benz and AMG chose to utilize the then-upcoming second generation C-Class, known within the two firms and Benz geek circles as the W203. In fact, the hot diesel C would be developed alongside the gas AMG C-Class, the C32 AMG.
Like the European market C32 AMG, the C30 CDI AMG (CDI denoting common rail, direct injection fuel delivery) was offered in all three W203 body styles: Sedan, station wagon and the hatchback Sportcoupe. It also shared the C32 AMG’s oh-so-subtle body kit, sport tuned suspension and brakes, chassis stiffening, 17” alloy wheels wrapped in high performance tires, and heavy duty 5-speed automatic transmission with manual shift mode.
The big departure, however, was found under the hood. Instead of the petrol-drinking supercharged 3.2L V6 of the C32, the C30 got its motive force from a double-overhead cam, 20 valve 3.0L inline-five turbodiesel. This powerplant was derived from Mercedes’ OM612 engine, which in regular form displaced 2.7 liters and was installed in Euro market C-, E- and ML-Class models, as well as the first generation of Sprinter vans and chassis-cabs to be offered in this country as Dodges and Freightliners. However, the embiggened AMG version (which, like all other modern AMG engines, was hand-assembled by one technician from bare block to finished engine) produced considerably more muscle than the 168hp and 270 lb.-ft generated by the passenger car version of the 2.7L OM612. The peak figures for the AMG version were a so-so 228hp, but a colossal 398 lb.-ft of torque.
Unsurprisingly, the modest power figure meant rather modest acceleration numbers. The factory quoted a 0 to 62 mph time of 6.8 seconds, but top speed was actually limited to 155 mph. Not quite the numbers you’d expect a late model sport sedan to put up, but mighty impressive for a diesel. And of course no gas burners in the class (e.g. Audi S4 and BMW M3) could touch it in the area of fuel economy, which was rated at 29.7 mpg combined for the wagon and 31 mpg combined for the sedan and hatchback.
Unfortunately, none of the aforementioned things were enough to make the C30 CDI AMG a success. A steep price tag and creature comforts like a CD changer (Remember those?) and leather seats being extra cost options didn’t do it any favors, but most of the rub with consumers probably lay in how it just wasn’t much a performance car compared to the average gas engined premium label sport sedan, wagon or hatchback. As a result, all three versions were discontinued after just three years on the market.
Worse still, the C30 CDI AMG’s brief life coincided with a five year window when Mercedes-Benz was not selling any diesel passenger cars in the United States, so we never got it. Of course, even if it was available in the U.S., we probably only would have gotten the sedan, and even then only in 90% of states. *Scowls in the California Air Resource Board’s general direction* Still, we think this country would have been better off having hot AMG-facilitated auto-igniting-diesel-on-piston action. No, it wouldn’t fix the deficit, make politicians put voters ahead of donors or banish Here Comes Honey Boo Boo from the airwaves, but it would be a nice start.