In the past few years, many people have made changes to adapt to a more environmentally-friendly lifestyle. Some people have even switched from petrol to diesel cars in an effort to increase their cars’ mileage and reduce the amount of fuel they use. Is diesel better for the environment than petrol?
For decades, diesel was mostly used for transporting goods long distances. However, in recent years, diesel cars have become much more popular, particularly in Europe. A large portion of new cars manufactured in Europe now use diesel. Petrol cars have an average energy density, or amount of stored energy in a given volume, of 34.6 megajoules per liter, and diesel cars have an average energy density of 38.6 megajoules per liter. On average, cars with diesel engines get significantly better mileage than cars with petrol engines. In some cases, diesel engines are as much as 1.5 times as fuel efficient as petrol engines. As of around 2015, diesel is cheaper than petrol in many European countries, but is still slightly more expensive than petrol in the United States. However, because a liter of diesel has better mileage, drivers can often spend less money on fuel when using a diesel engine. Furthermore, diesel engines have more torque than petrol engines, allowing for better acceleration, which increases their fuel efficiency.
Both diesel and petrol are made from petroleum and crude oil. Making diesel requires more crude oil per liter than petrol; however, diesel needs less refining than petrol, a process that uses energy. Diesel also emits much less carbon monoxide and hydrocarbons. Petrol engines produce about 28 times more carbon monoxide than diesel. Diesel engines emit much less carbon dioxide as well. Carbon dioxide is the biggest contributor to global warming, so this difference between the two fuel types is the main argument in favor of diesel engines as an eco-friendly option.
Although diesel engines emit less carbon dioxide and carbon monoxide, they still emit gases and substances that are harmful to the environment. Diesel fuel is much heavier and oilier than petrol because the engines emit nitrogen compounds. The fuel has improved greatly since the 1970’s and now is much cleaner with a reduced amount of particulate emissions and better engine performance. However, some scientists believe that the soot and black carbon from diesel may contribute to global warming. Studies have shown that diesel engines produce anywhere between 25 and 400 times the amount of soot and black carbon than petrol engines. These substances are not quite as much of a threat to the environment as the carbon dioxide emissions from petrol cars, but they still cause significant damage.
Scientists and manufacturers have been making attempts to reduce the dangerous emissions from diesel cars. Many new cars have direct injection systems that monitor fuel combustion, which helps to reduce emissions. Some cars also use CRT particulate filters and catalytic converters to decrease emissions. Furthermore, new cars often have emissions-control systems that reduce the toxicity of exhaust by treating it with a urea-based solution. The development of biodiesel is helping to improve the quality of diesel fuel as well. Biodiesel is usually made with soybeans in the United States and with canola in many European countries. It is effective in reducing tailpipe emissions, but some biodiesels take so much production energy that it is not much more environmentally-friendly than regular diesel. The development of biodiesel is still an ongoing process.
Is diesel better for the environment? On one hand, diesel cars emit much less carbon dioxide than petrol cars and because of the higher gas mileage, drivers will probably use less fuel by switching to diesel. On the other hand, diesel is not the perfect environmentally-friendly solution; the emissions do have a negative impact on the environment. However, scientists and researchers have realized the potential of diesel engines as an eco-friendly option. They are making efforts to improve the quality of diesel to lessen its dangerous emissions. Overall, although using diesel will not completely solve environmental problems, it is a better alternative to petrol.