The most sophisticated diesel cars in SA, such as BMWs X5sd, can use only ultra-low-sulphur diesel.
Don Boroughs Mail and Guardian Nov. 18, 2007
With high Sulfur fuel and Euro-2 emissions standards in place, I would not want to live there. Fortunately, Tier II/Bin 5 and the less stringent Euro V and VI w/ ULSD removes most of the problem - Ed.
The transformation of diesel's reputation -- from a sooty stain on the environment to the savior of the planet -- has taken place remarkably fast. This 180-degree turnabout became complete last month when BMW distributed half-a-million copies of a four-page, glossy brochure in the Sunday Times touting its new diesel X5 SUV as a solution to the greenhouse-gas effect.
Along with a photograph of a snow-capped mountain, BMW's marketers wrote: "With xDrive you'll get to see it. And with Ultra Low Sulfur Diesel the next generation gets to see it too."
The new diesel eco-hype is everywhere. Advertisements for Engen's Dynamic Diesel feature an image of flowers blooming out of a fuel-pump nozzle. The website for Volkswagen South Africa claims that with its "environmentally friendly" diesel engines "you can drive with a cleaner conscience, not just a cleaner engine".
But the dirty reality is that South African diesel fuel and diesel vehicles do not live up to this squeaky-clean image. Compared with petrol cars, oil-burners emit far more smog-forming nitrogen oxides and carcinogenic particulates.
Their advantage in greenhouse-gas emissions is also consistently overestimated. In fact, under some circumstances peculiar to South Africa, a diesel car may actually send more greenhouse gases skyward than a comparable petrol car. According to Don Anair, an American diesel-emissions specialist with the influential Union of Concerned Scientists, "the cleanest diesel vehicles are still not as clean as the cleanest gasoline vehicles".
South African diesel fuel is less dirty than it was before 2006, when legal Sulfur levels dropped from 3 000 parts per million (ppm) to 500ppm. But those current Sulfur levels are still 10 times higher than would be allowed in most European or Australian diesel and 33 times higher than in the 15ppm Sulfur diesel sold in the United States.
In South Africa, ultra-low- Sulfur diesel with 50ppm of Sulfur is becoming available at some Sasol, Shell, Total and BP filling stations, though not yet from Engen's flowering pump nozzles. This cleaner, more expensive diesel makes up only 3% of diesel sales, despite the recommendation from manufacturers that owners of their newest diesel models fill up with the pricier diesel. In fact, the most sophisticated diesels on the market, such as Honda's CR-V and BMW's X5sd, can only use ultra-low- Sulfur diesel.
Fuel retailers have muddled consumers by failing to distinguish between the two diesels as they promote their brands. Total South Africa, for example, calls both types of diesel "Ecodiesel", adding the word "Premium" to the 50ppm variety. Last month, the National Association of Automobile Manufacturers of South Africa issued a "diesel fuel quality advisory" complaining that fuel retailers fail consistently to make it clear at the pump which fuels have 500ppm or 50ppm of Sulfur.
"Meanwhile, we are being bombarded by advertising claims about 'our clean diesel'," says Stuart Rayner, chairperson of the association's fuel and emissions committee. "If you were to believe the advertising," he adds, a consumer would think that all diesel is now clean.
Diesel cars are also falling short of their green hype. Volkswagen's website fails to mention that its "environmentally friendly" diesel vehicles had to be removed from the American market this year because they could not live up to increasingly stringent US emissions standards. European regulations have always favored diesel engines by allowing them higher levels of particulates and nitrogen-oxide emissions than expected from petrol vehicles.
Washington is leveling the playing field, holding diesel vehicles to the same emissions rules. As a result, Volkswagen, the leader in US diesel passenger-car sales, had to withhold its diesel vehicles while it sorts out the technology required to meet the standards. Other manufacturers, from BMW to Volvo, have delayed introducing diesel cars into the US market for the same reason