Free Automotive Essay Sample

For more than 100 years, the two most prevalent types of engines used in the manufacture of vehicles have been mainly diesel and gasoline engines. Despite the fact that both are considered internal combustion engines, each type of engines comes with unique advantages and disadvantages when compared to its counterpart. The primary difference between gasoline and diesel engines is in the ignition process. Gasoline engines use spark plugs for the ignition of the fuel and air mixture, a process technically referred to as Otto cycle. On the other hand, diesel engines attain combustion by compression of the diesel fuel, a process technically referred to as diesel cycle. Although diesel engines are less popular than diesel engines, they are superior in numerous ways. The primary advantage of diesel engine is that they have higher engine efficiency, leading to improved fuel economy. Diesel engines have a reputation for producing higher levels of torque than gasoline powered engines, and boast of longer durability than gas engines. The absence of an electrical in diesel engines plays an integral role in improving its reliability. The distinctive benefits of diesel engines have helped increase their popular usage in commercial vehicles and large trucks. This is mainly because of the improved levels of torque, which facilitates greater towing capacity. The design of smaller cars relying on fuel efficiency can also benefit when using diesel engines. However, diesel engines are known to have excessive noise levels and emissions than gas engines. Nevertheless, advancements in the diesel engine technology are taking place to address these constraints. Presently, diesel powered cars have managed to reduce their emissions and noise levels to a rate comparable to their gasoline counterparts. Combining this with the actuality that diesel engines are more fuel-efficient than gas engines makes diesel-powered cars better than gasoline powered cars.

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Comparative Benefits and Disadvantages of Diesel and Gasoline Engines

In terms of fuel economy, diesel engines have a higher energy density than gasoline engines. The implication from this fact is that it requires more gasoline to produce an equal power output; as a result, diesel engine cars are more efficient in terms of per liter of fuel combusted. Diesel engines have been proved to use approximately one-third fuel when idle as petrol engines. This is a significant advantage for driving long distances. The economic benefits of diesel engines are higher than gasoline powered cars because of the high fuel efficiency and low costs associated with the diesel technology. Diesel combustion is considerably different from spark-ignition combustion used in gasoline engines in the sense that the entire air charge is at a temperature that is enough to ignite the fuel, and that each fuel particle gets the energy that ignites it from the hot air directly. It is apparent that direct injection systems reduce the consumption of fuel by 20 percent when compared to gasoline engines. The fuel consumption of diesels when compared with gas engines having an equal power is approximately 30-60 percent lower. In addition, the compression ratio of diesel engines is double the ratio in gasoline engines, implying that high levels of compression ignition pressure increases the thermal efficiency of diesel engines, which results in increased fuel efficiency than its gasoline counterpart. It is clear that, in terms of fuel efficiency, diesel engine cars are better than gasoline powered cars since gasoline ignites the fuel at relatively low temperatures and low pressures.

In terms of long-term durability and maintenance, diesel engines have an expensive initial cost and excellent durability. On the other hand, the average gasoline engine has been found to be good for only approximately 200,000 kilometers before requiring a rebuild and not designed to pull heavy loads continuously. Diesel engines have been proved to have a mileage thrice this amount prior to requiring an overhaul. The factual observation is that diesel engines have a longer lifespan than gasoline engines. This is mainly because diesel engines have less wear and tear than gasoline engines. For instance, diesel cars can easily attain a mileage of about 250,000 miles and still have some life left in them. Diesel engines have lesser maintenance costs than gasoline powered cars since they rely on air compression for creating combustion, whereas gas engines rely on a mixture of fuel and air. The noticeable difference for car owners is that diesel engines do not need spark plugs and constant tune-ups. In addition, fewer parts are used in the production of diesel engines, implying that repairs are less costly than for the case of gasoline engines. However, in terms of short-term maintenance, it is apparent that regular maintenance of diesel engines is more costly than for gasoline engines because of the larger volume of oil present in the engine and because of the need for regular servicing of oil filters and water separators. Modern gasoline engines have an advantage in terms of short-term maintenance because of the extended intervals needed to service its components such as engine oil and spark plugs.

In terms of power and torque, gasoline engines have a significant advantage in horsepower, whereas diesel engines produce more torque than gasoline powered cars. The design elements of the engines reveal that gasoline engines rev faster and have the capability of reaching higher peaks than the average diesel engines, which allows gasoline engines to achieve greater horsepower numbers than diesel engines. However, diesel engines have an edge in terms of the pulling force and towing capacity. The torque advantage associated with diesel engines makes them suitable for pulling relatively heavy loads in steep inclines. The relatively high-compression ratio required for igniting a diesel fuel makes its power and torque relatively low in the same rev range than gasoline engines. Therefore, gasoline powered cars have greater power than diesel powered cars.

In terms of emissions, diesel cars are known to have excessive levels of smelly emissions when compared with gasoline-powered cars. Diesel is extremely smelly and greasy, unlike gasoline that mostly evaporates. Irrespective of the efforts initiated by oil companies to produce diesel with reduced sulfur levels, the smell of combusted diesel is still worse than combusted gasoline. It is apparent that diesel cars are still lagging behind in terms of Nitrogen Oxide emissions, which makes gasoline cars more environment friendly than diesel cars. Another disadvantage of diesel cars is that they have higher levels of noise than gasoline cars. Irrespective of enormous advancements to improve the engine-noise ratio, it is apparent that diesel engines are still louder and vibrate more than gasoline cars. When idle, the shake and clutter of diesel car is noticeable, whereas is tough to determine whether a gasoline engine is running. Even under low accelerations, diesel cars are still noisier than gasoline cars.

Another advantage of diesel cars is that they are safer than gasoline cars because diesel does not explode like gasoline. This makes diesel cars safer than the average gasoline cars. In cases of accidents, owners of diesel cars would not have to worry about the car exploding. Additionally, diesel cars have alternate sources of fuel because they can use bio-diesel, which makes diesel cars more versatile than gasoline cars; making such a switch in diesel cars do not need massive modifications.


It is apparent the choice of a better car pins down to the intended use and perceived mileage. Overall, the advantages of diesel cars far outweigh gasoline cars. In addition, improvements in the diesel technology are embarking on the development new diesel engines having minimal noise and vibrations and reduced emissions. Combining this with the actuality that diesel engines are more fuel-efficient than gas engines makes diesel-powered cars better than gasoline powered cars.


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