What is a Clean Diesel engine?

A diesel engine has turbo or not, is more polluting or less depending on their emissions of unburned hydrocarbons

All you have ever suffered an attack of some squid on the road. I do not mean an alien, but a vehicle with diesel engine was not good thing and gave you a black smoke that darkened the sky. Contamination is not dangerous, as you see, even more.

A diesel engine has turbo or not, is more polluting or less depending on their emissions of unburned hydrocarbons

A diesel engine has turbo or not, is more polluting or less depending on their emissions of unburned hydrocarbons (HC), nitrogen oxides (NOx), particulate matter (PM) and sulfur oxides (SOx). Go over your minicourse air pollution, the CO2 is unimportant, as it is not a pollutant gas.

Successive antipollution regulations have been gradually putting an end to this, but especially in the U.S. and Japan. It was not to sell or one in those countries. The manufacturers’ response to this challenge is called Clean Diesel. How far is it?

The case of the United States and Japan

Why in these countries, diesel engine has had so little success? From the 70s began to regulate the emissions issue, and clearly these engines were losing. The gasoline used tetraethyl lead also fell short, precisely.

In the Japanese case, it began to harden both legislation that manufacturers began to remove diesel catalogs, until they completely disappear in 2007.

In the U.S., the laws were very difficult to beat for the Diesel, so gradually faded away. They left a very bad reputation among drivers, just look at the topics that exploits this announcement of BMW 335d Clean Diesel aired on Super Bowl 2011.

And in Europe, what?

The old continent, which has always walked little oil, began to use more and more oil, especially from the technological advances of the late 80s and early 90s: appears Turbodiesel and Fiat invented Common Rail (the direct injection). Gradually, the oil begin to compete with gasoline.

In the early 90’s are Euro regulations, which introduce fuel injection in gasoline, catalytic converters and unleaded fuel. Later, the Diesel also start using catalysts, from Euro 2. In 2001 appears Euro 3, Euro 4 in 2004, and in 2011 Euro 5.

However, European legislation is softer than the Japanese or American, to Euro 4 did not begin to be widespread use of the particulate filter (DPF or FAP). Now no Diesel comes without it. Manufacturers began to improve the engines to the point of eclipsing the gasoline in some countries.

How to reduce pollution from diesel engines?

The first problem comes from the fuel, usually contains sulfur diesel, and this generates the SOx when burned. In U.S., Japan and Europe has gradually adopted the low sulfur diesel. The diesel “expensive” just has sulfur in its composition, is more expensive to refine, but pollutes less.

To reduce NOx and HC takes the catalyst, which converts most polluting exhaust gases of nitrogen, oxygen and carbon dioxide: they are present in normal air. Obviously, the better the engine, the less it depends on the work of the catalyst. For example, the famous EGR reduce NOx.

There remains the issue of particulate matter (PM), which are reduced with particulate filters, accumulating them and frying them after a while. Fail to remove the smaller particles (PM10 or less) but big neutralize, which are trapped in the filter. When burned gases become safer.

Here’s how the urea injection system

There are more technical, such as selective catalytic reduction (SCR), which leads to the famous urea, a compound that is injected after combustion to convert NOx gases cleaner. This system requires a urea tank to be recharged in the reviews, commercially usually it is called AdBlue.

The Clean Diesel engines use all these techniques to minimize emissions and overcome the toughest environmental regulations. In Europe that come with Euro 6 (2014), but in the U.S. and Japan already have gone before Europe.

Only U.S., partnered BMW with Daimler and Volkswagen to create a range of engines cleaner than normal. The result of this union has come a range of models that not only boast performance or low energy, also exceptionally clean, now they can fill up with a very low sulfur diesel (ultra-low-sulfur diesel or ULSD).

Audi Clean Diesel Range communion dressed in pure white and wicked

Clean Diesel models List
By default, all these models are for North America, including the latest developments in the Hall of Los Angeles and upcoming releases:
Audi A3 2.0 TDI, A6 3.0 TDI, A7 3.0 TDI, A8 3.0 TDI, Q5 3.0 TDI, Q7 3.0 TDI
BMW: 335d (E90 model), X5 xDrive35d
Mazda: Mazda6 2.2 SKYACTIV -D (2014)
Nissan X-Trail 2.0 dCi (Japan)
Mercedes-Benz: E 320 BlueTEC, GL 320 BlueTEC, ML 320 BlueTEC, R 320 BlueTEC
Volkswagen: Golf 2.0 TDI, Jetta 2.0 TDI, Touareg 3.0 TDI

All these models are considerably cleaner than their European counterparts. Some can be ordered in Europe, but as they have sophisticated anti-pollution systems are more expensive. For example, the Audi Clean Diesel 1500-2000 euros typically cost more, identical performance and consumption.

Can you infer that diesel cars sold in Europe are dirty? Yes and no, comply with regulations. Good maintenance of the car depends keep emissions in check. When you see a squid, you know the case that the owner makes the car or going to the workshop. Have a squid? NOT HERE!