Diesel Fuel Once Again Taking Over Petrol
Once a dreaded word that made environmentalists hyper active, and largely associated with noisy hefty cargo trucks emitting cloud of sooty smoke, diesel engines have come a long way. Today, they are universally acclaimed as more efficient than their gasoline counterparts. History may have been harsh on this segment of engine technology, but with intensive research and development efforts preceded by its invention in the first place by Rudolf Diesel in 1892, diesel engines are now the in-thing in the automotive landscape around the world.
The beginning of this journey which seems to be on the uphill now, has been humble and secondary to gasoline. The diesel engine's invention can also be credited to the gasoline engine that was patented by Nikolaus August Otto in 1876. Otto's mechanics continue to fire today's gas engines, but in those days his engine used only 10 per cent of the energy produced by the fuel while the balance was frittered away.The invention of diesel engines was largely to produce a higher efficiency engine based on a more refined combustion cycle. The late start ensured that gasoline gained a foothold in the first lap. But today it is diesel that offers more potential for future development.In a lot many ways however, a diesel and gasoline engine is very similar to each other. They both use internal combustion method to convert chemical energy from the fuel into mechanical energy. Both diesel engines and gasoline engines convert fuel into energy through a series of small explosions or combustions. Both also share a four-stroke combustion cycle.
So why is it that diesel is considered to be noisier, environmentally hazardous and more expensive to maintain?
The major difference in the two engines is the way these explosions happen. In a gasoline engine, fuel is mixed with air, compressed by pistons and ignited by sparks from spark plugs. In a diesel engine, however, the air is compressed first, and then the fuel is injected. Because air heats up when it is compressed, the fuel ignites.
Compression ratio is another area where the two engine systems are remarkably different. Unlike a gasoline engine which compresses at a ratio of 8:1 to 12:1, a diesel engine compresses at 14:1 to 25:1. Clearly, diesel engines generate much more power than their gasoline counterparts and that is a big reason why they are in so much demand today even in markets like the US which had rejected it in the 80s.
Consider this:
- Four of the top 10 most fuel-efficient vehicles are diesel powered.
- Registration of diesel passenger vehicles in the USA has grown 80 per cent since 2000.
- Sales of new diesel cars in Europe continue to rise as consumers search for cost-saving fuel. One of the surveys shows that diesels accounted for 49 per cent of the total European car market at the end of 2005. Diesel is now set to overtake petrol as the primary fuel for new passenger vehicles in Europe.
- Most analysts expect the diesel trend to continue.
So,Why Is This Change?
The change in this image is largely due on two acounts. First is the economy angle, whereby diesel is today a cheaper fuel in most of the developing countries; and secondly, due to a series of strict emission standards, this fuel now has a much greener hue as opposed to a gasoline engine.
Experts world over believe that today, diesel is the most efficient internal combustion engine; helping companies to save money and the country in reducing its petroleum consumption. They are renowned for running hundreds of thousands of kilometres or operating hundreds of thousands of hours. It delivers the torque and power necessary to complete tough jobs.
They are also cleaner than ever before, and in the next few years, the diesel industry is all set to virtually eliminate key emissions associated with on- and off-road diesel equipment. This environmental progress is the result of the new clean diesel system - combining cleaner diesel fuel, advanced engines and effective exhaust-control technology.
On the economy front, not only is diesel cheaper due to fiscal reasons - it is a fuel linked directly with freight which is linked directly with inflation -, it is also a petroleum-based fuel with high energy content, helping a vehicle powered with this technology to go farther per litre than most other alternatives.
Refiners are working to reduce the sulphur content in diesel fuel. New, ultra-clean fuel is important because sulphur tends to hamper advanced exhaust-control devices in diesel engines. For example, lead once obstructed the catalytic converters on gasoline cars. Just as taking the lead out of gasoline in the year 2000 enabled a new generation of emissions control technologies, so will removing the sulfur from diesel help usher in a new generation of clean diesel technology.
In this era of sky-high energy prices, more diesels are discovered as a fuel-saving alternative to gasoline that does not require sacrifices in power and performance. Diesel is the world's most efficient internal combustion engine, returning 20 to 40 per cent greater fuel efficiency than comparable gasoline engines. Increased use of diesel vehicles enhances our national security by reducing our dependence on foreign oil.
Over the past 15 years, advancements in diesel technology have been extraordinary. The progress has been substantial, such that emissions levels from clean diesel engines are now competing with alternative technologies, such as CNG. When compared on a cost basis, the clean diesel options may become more cost-effective than the more expensive and less widely available alternatives.
New clean diesel technology is poised to establish a new environmental benchmark for lower emissions, increased energy efficiency, and reliable power and performance. Programmes that seek to upgrade existing engines reduce unnecessary vehicle idling, and target vehicles that are gross emitters will play an increasingly important role in the future of diesel technology. Thanks to these advancements, diesel technology is expected to remain the predominant source of power for automobiles in the foreseeable future.
