How Clean Are Clean Diesel Cars? 5 Facts Based on Pollution

February 21, 2012

A second look at claims about clean diesel cars. Find out how clean diesel technology works, and see how the EPA scores different models.

A Clean Diesel Car

Clean diesel cars, like the VW Polo, are being promoted as a way to help the environment and as a better alternative to standard gasoline engine powered vehicles. Clean diesel technologies have improved the quality of clean air emissions in diesel powered vehicles considerably in recent years. However, before you rush out and purchase a clean diesel Jetta or a bio-diesel powered car, there are some facts you should be aware of.

Increases Air Pollution
Many car buyers only compare the fuel economy of the vehicles they are considering. Although some believe the amount of fuel a vehicle burns is the primary cause of global warming pollutants, there are other are other factors that need to be considered.

While diesel fuel generally produces more energy or miles per gallon than gasoline, it also has a much higher carbon content. In fact, diesel fuel produces approximately 13 percent more CO2 gas per gallon of fuel burned, compared to gas engines.

In Environmental Protection Agency tests measuring how much air pollution a particular make and model vehicle produces, hybrid gasoline-based vehicles scored much higher than clean diesel vehicles. In recent years, Honda Civic hybrid vehicles have scored an average of 9, while diesel Jetta cars have averaged scores of between 5 and 6. For the purpose of these tests, 1 is the lowest score and 10 is the highest. Higher scores are awarded to vehicles that cause less air pollution.

Creates More Oil Dependence

In addition to creating more CO2 gas, diesel fuel can also lead to greater oil dependence than fuel-efficient gasoline engine powered vehicles or hybrid vehicles. A joint Environmental Protection Agency and Department of Energy study showed that about 13 percent more raw crude oil is needed to produce a gallon of diesel fuel than is needed to make 1 gallon of gasoline. Therefore, unless the MPG difference between a diesel and gasoline engine powered vehicle is significant, a diesel powered vehicle will actually consume more crude oil.

Increases Carbon Footprint
Because even clean diesel powered vehicles create more CO2 gas than fuel-efficient gasoline powered vehicles or hybrid vehicles, they also have a larger carbon footprint. The carbon footprint of a vehicle provides the best estimate of how much greenhouse gas pollution a particular vehicle will produce. For example, popular Honda Civic hybrids produce about 4.4 tons of CO2 gas per year. On the other hand, a clean diesel powered Volkswagen Jetta produces about 6.4 tons per year, or about 45 percent more carbon-based emissions than the gasoline hybrid vehicle.

Even Clean Diesel Vehicles Can Cause Illness
Although modern clean diesel is much better than the diesel fuel that was created and formulated in past years, exhaust from diesel engines can still cause serious illness. Breathing in even relatively small amounts of diesel exhaust can cause serious illness--especially in children, the elderly or the chronically ill. Even very short term exposure can cause existing allergies to worsen or cause symptoms of asthma or bronchitis.

How Clean Diesel Technology Works

Clean diesel aims to be more environmentally friendly than standard diesel. It also provides a longer lasting fuel for your engine. Clean diesel technology has advanced progress on energy efficiency and environmentally friendly fuel, and diesel cars have become more popular. Clean diesel outperforms even treated fuel as the energy of the future.

What Is Clean Diesel?
Clean diesel is low in sulfurs, which mean that the engines burn the liquid more cleanly, and, so long as the engine itself is designed to be environmentally friendly, will pollute the environment a lot less than ordinary systems. TDI and hybrid engines can use clean diesel as a standard fuel, and this means they produce a lot less pollution than standard systems. Hybrid and TDI engines are usually fitted with filters and catalytic converters which can burn off nitrous oxide (or N2O), which is a big cause of pollution from diesel engines.

Clean Diesel Makes a Difference
Clean diesel can make a big difference to the environment. The diesel known as an Ultra-Low Sulfur Diesel has around 15 parts of sulfur per million, rather than the 500 parts per million of typical diesel engines. Studies have shown that clean diesel produces nearly 40 percent less diesel particles than ordinary fuel, which is a significant difference. As a result, clean diesel has been called a lean burn technology by the EPA. With this designation, people who use clean fuels can claim over a thousand dollars worth of tax credits. This means that users can both help the environment, and assist their own wallets at the same time. Another advantage of the new fuel is that the engine works better, and is more efficient when compared to typical gasoline cars.

The diesel vehicle has improved a long way from when they were first invented. The engine is now a lot quieter, and there is much less smoke than in previous decades. TDI engines have been a great advancement in the use of diesel in cars, and utilizing a clean diesel fuel means that you also have the advantages of heating a fuel without having to risk the spark which is a typical part of the gasoline engine. In all, clean diesel is a great invention which can really benefit you, your car, and the environment.