Are Diesel Fuel’s Days Numbered?

2015 Volkswagen Golf GTD Wagon; Source: VW Germany
Source: Volkswagen

After decades of being stigmatized in the American market, diesel-powered cars are finally starting to take off. In the first half of 2014, sales rose 25 percent thanks in part to greater fuel economy and reliability over traditional gasoline engines, and the successful rebranding of the fuel as “Clean Diesel,” an eco-friendly alternative to gasoline.

But the good times may be coming to an end for diesel fuel. After years of being touted as the future of the internal combustion engine, European governments are enacting strict new measures to reduce production, and in some cases, ban the cars outright.

Europe’s strict new actions against diesel will likely set the tone for the fuel’s automotive future, and has the potential for major repercussions throughout the automotive industry. Today, diesel-powered cars account for the majority of new car sales in Europe. Diesels are so popular, in fact, that in Europe they account for 81% of BMWs, 71% of Daimler cars (including Mercedes-Benz and Smart), and 90% of Volvos sold.

Air Pollution Reaches High Levels Across London
Dan Kitwood/Getty Images

Like California’s ongoing issues with smog, the air quality of many major European cities has become exceedingly dangerous, and it can be directly linked to diesel exhaust. In 2014, areas of London, Athens, Berlin, Brussels, Madrid, Rome and Paris all had air quality that failed to meet the European Union’s standards. As a result, Anne Hidalgo, the mayor of Paris, announced that the city would work to ban diesel-powered cars from the city by 2020 – a bold claim, as diesel-powered cars account for two-thirds of all car sales in France. London followed suit, with mayor Boris Johnson proposing to double the congestion charge for diesel-powered vehicles driving in the city center to 20 pounds, and enact a similar ban to go into effect sometime next decade.

Source: Mercedes-Benz
Source: Mercedes-Benz

The end of the global love affair with diesel will be a tough one. It started in the 1970s during the first oil crisis, when it was cheaper to refine than gasoline. Mercedes-Benz was an early and enthusiastic convert, and its long-running 240D models are still a common sight on roads today – and a testament to the longevity and durability of diesels.

But there were some pretty serious problems along the way. Diesels were notably slower than their gasoline-powered counterparts, and they developed a reputation of belching about as much black smoke from their tailpipes as a semi truck.

Source: Mercedes Benz
Source: Mercedes Benz

General Motors all but poisoned the well for Americans with its range of atrocious diesel engines built between 1978 and 1985. Ignoring the fundamental engineering differences between gasoline and diesel engines (and there are many), GM modified conventional Oldsmobile engines to run on diesel. But high heat and compression wreaked havoc on the engines, causing most to seize well before they hit the 100,000 mile mark. Years of recalls and class-action lawsuits were enough to ruin diesel’s reputation for an entire generation of Americans.

Advances in technology in the ’80s and ’90s made diesels more attractive, and today, they achieve 25 to 30 percent better fuel economy than gasoline-powered models. They also offer better low-end torque, and have a reputation for higher reliability.

Source: Thinkstock
Source: Thinkstock

In 2008, Automotive News published a glowing piece called “For diesel engines, the future looks bright” as sales of diesels overtook gasoline-powered models in Europe for the first time. That year, a panel of automotive executives predicted that as many as 20% of new vehicles sold in the U.S. by 2018 could be diesel-powered.

In 2014, only 150,000 diesel-powered cars were sold in America, but there are 46 diesel models currently available in the U.S. including trucks, and the stigma associated with the fuel seems to be gone –  at least for now.

Jaguar XF Diesel
Source: Jaguar

The removal of sulfur from diesel fuel, and advances in filtering and emissions technology have made smoke-belching diesels a thing of the past, but nitrogen dioxide, hydrocarbons, ozone, and diesel particulate matter are still troublesome byproducts, and they’re starting to take lives.

In 2012, the World Health Organization’s International Agency for Research on Cancer classified diesel exhaust as a “Group 1 Carcinogen,” citing an irrefutable link between exposure to diesel particulates and lung cancer. It is believed that diesel pollution is a factor in over 29,000 deaths annually in England alone.

Porsche Macan S Diesel
Source: Porsche

For now, automakers are unwilling to completely give up to ghost on diesels, and are proposing the use of hybrid technology to help reduce emissions, but the future looks dim. Speaking with Automotive News, former Ford engineer Tom Watson assessed the feasibility of cleaning up the “Clean Diesels,” and concluded “More reduction can be achieved with higher levels of electrification of the diesel engine, but with diminishing returns.”

After decades of looking like a cheaper and more efficient alternative to gasoline, the diesel engine may soon join the Wankel rotary as another failed version of the internal combustion engine. For Europe, the end of diesels would mean clearer skies and radical shift in the transportation habits of millions of people. In America, it means diesels would most likely fade into obscurity. Once poised to take over the world, the diesel engine now looks more and more like an automotive albatross.

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