Almost as soon as the gasoline-powered internal combustion engine was invented, people began trying to come up with something better. After working through the 1880s and ’90s, German engineer Rudolf Diesel thought he had the answer. Patented in 1893, his eponymous engine promised greater efficiency at a lower cost, and had the potential to transform industry, with his engines eventually finding applications in locomotives, aviation, marine, and heavy industry.
Instead of using a spark to combust fuel, diesel engines use an ultra-high compression system to ignite the fuel, allowing diesel fuel to be cheaper, lower quality, and less refined. They’re often cheaper to run, return better mileage, and more torque. But they also require engines that can take the punishment of high compression, with coarser fuel often comes dirtier emissions, and frankly, your standard diesel car wasn’t going to win many drag races.
For years (at least in the U.S.) the most common diesel cars were strange, slow imports from Europe that belched black smoke, smelled, and weren’t for anybody in a hurry. Still, the technology had massive potential in the auto industry, and automakers around the world have spent years funneling billions into developing cleaner, faster, more powerful diesel engines. But it’s always been an uphill battle. It took decades to overcome its grimy image, and just when it seemed like it could catch on here, Volkswagen’s massively successful “Clean Diesel” technology turned out to be a sham, and has erupted into a scandal has the potential to end the diesel car once and for all.
But this is far from the first diesel scandal. While diesels have been commonplace in Europe since the 1970s, Americans have been notoriously wary of diesel engines for almost as long, and to be honest, they have plenty of reason to be. Here are eight cars that tell the sad, strange story of diesel in America.
1. Mercedes Benz 300SD Turbo Diesel
Mercedes had toyed with diesel-powered cars as far back as the 1930s, but in 1978, it made history by launching the 300SD, a turbocharged five-cylinder diesel model exclusively for the North American market. Based on the full-size S-Class sedan, the SDs were pure luxury inside, and with fuel economy in the mid-20s, and diesel cheaper than gas, it was a popular choice for the well-heeled in the waning days of the gas crisis. The Mercedes diesels of that era are so well-built, that nearly 40 years later, not only are thousands of them still on the roads (seriously, check Craigslist), but they can be converted to run on biodiesel with an afternoon’s worth of work.
2. Oldsmobile Diesel
Released for 1979, the Oldsmobile 350 cubic inch Diesel V8 was an $850 option that promised to return 30 miles per gallon – an astonishing feat for a full-size sedan. What it didn’t advertise was a 20 second zero to 60 time, a wheezing 90 horsepower, clouds of black smoke, and a tendency to grenade after less than 100,000 miles. Loosely based on the bulletproof 350 cubic inch gas-powered V8, GM rushed the diesel into production without fully testing whether or not its new engine could handle the extremely high compression of diesel. It couldn’t.
In severe cases, the high-compression of the engines simply sheared the head bolts off, causing coolant to pour into the cylinders and seize the engine. If that didn’t get you, then the lack of a water separation system caused the fuel lines and engine to rot from the inside out. And with GM’s mechanics largely unfamiliar with diesel engines, Mr. Goodwrench couldn’t do very much to help. Astonishingly, the Olds diesel soldiered on until 1985, even after owners filed, and and eventually won, a massive class action lawsuit against GM for its terribly-built engines. By then, Oldsmobile engine disaster had all but made diesel a dirty word in America. If your parents are still skeptical about diesel cars, this is probably why.
3. Dodge Ram Cummins Turbo Diesel
While diesel looked like it was down for the count when it came to passenger cars, the Big Three were having some success with diesels in their pickup trucks. With better fuel economy and all that torque, diesels were perfect for hauling, especially when speed didn’t matter. But unlike the Olds 350, the Big Three went to the professionals for their truck oil burners. Ford went to International Harvester, GM went to Detroit Diesel (which it then owned), and Dodge went to Cummins, all makers of diesels for over-the-road trucks. Released for 1989, the Dodge Ram Cummins Turbo Diesel was a surprise hit for the company. It had a direct-injected inline-six that eliminated the need for glow plugs, and was significantly more modern than its competitors’ naturally aspirated V8s. Today, diesel-powered pickups are still in high demand, and retain their value far better than their gas-powered counterparts.
4. 1989 Audi 100 TDI
It didn’t come to our shores at the time (Audi was in a little bit of trouble here back then), but the now-infamous “TDI” acronym first appeared on a Volkswagen AG product on Audi’s full-size diesel-powered 1989 100 sedan. With a turbocharged, direct injection 2.0 liter inline-five, the 100 TDI was good for 120 horsepower, 265 pounds-feet of torque, and an impressive 30+ miles per gallon. While the U.S. had all but left diesel cars for dead, the Europeans were ironing out the kinks, and buying them in droves.
5. 1996 Volkswagen Golf TDI
With diesel being cheaper and more efficient than gas, diesel cars were taking off in Europe. In the U.S., however, diesel was still considered to be a four-letter word. Still, Volkswagen introduced its peppy TDI engines to the Americans in 1996 by way of a 2.0 liter inline-four available in the Golf and Jetta. For the better part of the decade, Volkswagen’s TDI cars all but had the market to themselves.
6. 2005 Jeep Liberty
By 2005, while diesels were threatening to overtake gas-powered auto sales in Europe, low-sulfur diesel was introduced in America. With that, automakers finally saw the potential in the engine’s ability to deliver strong fuel economy and low emissions, especially at a time when emissions and economy standards were getting stricter by the year. Chrysler was one of the first American companies to test the waters, offering a 160 horsepower Italian-built oil burner in its midsize Patriot SUV. Perhaps unsurprisingly, it wasn’t exactly a hit.
7. 2007 Mercedes-Benz E-Class BlueTec
Introduced at the 2006 North American International Motor Show, the BlueTec diesel engine was designed to slay the “dirty diesel” stereotype once and for all. The BlueTec E -Class was quiet, comfortable, and could even keep up with traffic. At the heart of the system is a separate tank for water-urea-based BlueTec fluid, which is injected into the car’s exhaust system and dramatically lowered the car’s emissions. Since then, almost all modern diesels have adopted similar systems. Ironically, Volkswagen and Audi both licensed BlueTec technology from Mercedes, but they opted not to use in on their ’09-’15 2.0 liter TDIs – the cars at the center of their current crisis.
8. Volkswagen TDI
Released for 2009, the ’09-’15 TDI Volkswagens equipped with the EA189 2.0 liter turbo-diesel engines are the focal point of this scandal. Eschewing BlueTec technology because it claimed the cars could meet emissions standards without it, over 11 million cars were programmed with a “Test Mode” defeat device that allowed the car to pass government testing, then shut off during everyday driving. As a result, Volkswagen is being forced to recall all 11 million vehicles and make them compliant, while facing fines of up to $18 billion in the U.S. alone. While the situation is disastrous for Volkswagen, it could prove to be the final blow for the engines in the America. In 10 years’ time, landscape of diesel passenger cars could look very different.
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