With the high price of gasoline, do you wish that your vehicle got better fuel economy? Wouldn’t it be nice if it got better fuel economy, but still provided as good or better performance? With a diesel engine, you can have all that and more. Diesel engines can get better fuel economy, perform better, and be more reliable than gasoline engines. Unfortunately, there are many misconceptions concerning diesel engines which may be holding people back from buying diesel powered vehicles.
It’s a known fact that a gasoline engine of similar size and power output burns more fuel for the amount of work done than an equivalent diesel engine. There are many reasons for this. Diesel fuel contains about 147,000 BTUs of energy per gallon compared with gasoline’s 125,000 BTUs, so when that energy is converted to work by the engine, the gasoline engine requires a larger amount of fuel than the diesel engine does to do the same amount of work. The direct fuel injection systems used in diesel engines are much more efficient than the manifold fuel injection systems used in gasoline engines, helping to give diesels better fuel economy. Because of this, gasoline engines burn almost 3 times as much fuel when idling than diesels do. For example, if two nearly identical GM trucks are compared, the only difference being that one has the 6.0L gasoline engine and the other has the Duramax 6600 diesel engine, the fuel economy difference is incredible. The gas truck gets an average of 12.5 mpg whereas the diesel gets around 20 mpg. Over 100,000 miles of driving, the diesel will save you $1500 to $2500 in fuel costs depending on how often you tow trailers. As a general rule, a diesel powered truck or SUV gets 6 to 8 miles per gallon better than a comparable gasoline powered truck or SUV. Over the life of the vehicle, that’s a lot of savings and can easily overcome the additional cost of the diesel engine. Even though diesel fuel is general priced about the same or perhaps a little higher per gallon than gasoline, you still save money. One thing to keep in mind is that the price of diesel fuel usually fluctuates less than gasoline, so you have to worry less about fuel price increases caused by political issues or natural disasters. It is important to note that there are many smaller vehicles also available with diesel engines, including VW cars and the Jeep Liberty CRD which is a small SUV.
Since diesel fuel is easier to refine, it would actually be cheaper if there was more demand for it since the fuel loads delivered to stations would be larger. Biodiesel is an alternative fuel which will come in handy as our petroleum supply diminishes, and is made from soybeans or waste cooking oil. It can be mixed with diesel fuel, or can be run just by itself. Its popularity and availability is increasing, and it is already used by some cities in their busses.
Diesel engines can also offer higher performance in many situations than gasoline engines can. Although gasoline powered vehicles are often quicker when unloaded in off-the-line acceleration because of the characteristics of gas engines which allow them to rev faster and higher, this trend has been changing. Newer diesel trucks, for example, are able to accelerate faster than their gasoline counterparts because their power ratings have been increased substantially in the last few years, which allow them to overcome their slower revving characteristics. Diesels have a much larger amount of low end torque than gas engines which means that they pull heavy loads and hold their speed on steep hills a lot easier than gas engines. This is especially noticeable in vehicles with manual transmissions, where you can stay in high gear on hills that you would have to downshift a gear or two in a gasoline powered vehicle.
Diesel engines of the past have been known for their smelly exhaust, black smoke, and emissions. Engine technology is advancing with computer controlled systems such as improved turbochargers and pilot ignition which have eliminated the black smoke, which was caused by too rich of a fuel/air mixture. The exhaust smell has been reduced with the elimination of the smoke. Newer blends of fuel such as low sulfur diesel help to reduce the emissions such as NOx which contribute to smog. They now have lower emissions than many gasoline fueled engines.
Diesel engines ignite their fuel by compressing it to high pressure and temperature which causes it to ignite itself rather than gasoline engines’ spark ignition systems which use spark plugs to ignite the fuel. Because of this diesels were generally more difficult to start in cold weather since the cylinder temperature would be too low for the fuel to easily ignite itself. This has all changed in recent years because of computer controls that inject the fuel later in the cycle as well as improved glow plug and manifold air heating systems which help to raise the fuel and cylinder temperatures. While you may spend more for short term maintenance for a diesel engine for reasons such as larger oil capacity, long term maintenance items like tune-ups are never needed because diesels do not have a spark ignition system. Overall, diesels will run about three times as many miles as gas engines will before needing a rebuild.
When you add it all up, many people can find just what they want in a diesel powered vehicle. Because of the technology incorporated in newer engines, all of the downsides to diesels have been erased. Better fuel economy, higher performance, and more longevity can be had with a diesel powered vehicle and you will also save money in the long run since your vehicle will last longer, and you will spend less on fuel.