Engines to suit your needs

We ride our car or take the bus to our destination every day, but while you sit there comfortably, have you ever wondered how the engine works? There are many different variations of the engine available. So in this article, we will focus primarily on the differences between petrol and diesel engines and what difference that makes.

Petrol engine works on the Otto Cycle, named after Dr. Nikolaus August Otto, who theorized that there is a constant volume at work. To start a petrol engine of an automobile, air and petrol are mixed in a carburetor and are then transferred to the designated cylinder where with the help of an electric spark plug the composition is ignited resulting in what we call “starting the engine”. The compression ratio is lower in the petrol engine therefore the power produced is also lower. Without an electric spark plug, there is no way we can start the petrol engine of an automobile. The fuel that is used in a petrol engine has higher volatility, which means the fuel being used is highly unbalanced and uncertain.



You may have noticed that a lot of automobiles that are predominantly used as small passenger vehicles or a family car run on petrol. It is because lighter vehicles do not require that much power, hence they are mostly fitted with a petrol engine. But lighter does not mean it is more economic in terms of fuel consumption. It may come as a surprise but fuel consumption is higher in a petrol engine. This is due to the fact that the power it generates is low and has to keep burning more fuel in order to generate more power. Therefore, there is more consumption of fuel. You may also have noticed that petrol engine vehicles are lighter in comparison to their counterparts. The initial cost of the engine is also lower as well as the maintenance cost. Overhauling however needs to be frequently done to preserve the life of the engine and the chances of your petrol engine not starting in bad weather conditions or in difficult situations is lower.

Coming to diesel engines, this engine works on the Diesel cycle, named after Rudolph Diesel who put forward the idea of attaining motion through constant pressure. The fuel which is diesel in this case, is injected using a fuel injector and is mixed with air inside the cylinder. A diesel engine does not require any sort of external electric spark plug because the engine is ignited by applying heat generated through compression inside the cylinder. Due to the constant pressure, the compression ratio is higher compared to a petrol engine. And the higher the compression ratio, the higher the power it produces. As mentioned above, there is no need for an electric spark plug but there is a fuel injector fitted to inject fuel into the cylinder. In contrast to its petrol counterpart, the fuel these engines use is of low volatility, hence lower risk of something going wrong.

Mostly automobiles which need more power to function such as buses, trucks and locomotives have diesel engines since the power it produces is higher. Now the strange thing is, a diesel engine is comparatively heavier than the petrol engine but the fuel consumption is less. This is because it produces more power in ratio compared to that of a petrol engine, hence it requires less fuel to generate the same output. So why don’t people buy automobiles fitted with diesel engines since the fuel consumption is lower and it produces more power? It’s because the diesel engine has a higher maintenance cost as well as a greater initial cost. In the long run, owning a diesel engine vehicle will run your wallet dry. There is also a higher chance of your engines not starting in bad weather or adverse situations. The sound and rattling made by a diesel engine is also louder and disturbing. You may have noticed this while sitting on a bus or other heavy vehicles.

As technology is advancing rapidly, the differences between the two engines is slowly being bridged. Parts or components of a petrol engine may now be found in diesel engines as well and vice versa. It is also a matter of preference as to what type of engine you want. If luxury is what you’re looking for or just to drive around the city or for commuting to and from work, it would be best to buy a petrol engine, since the initial cost and maintenance costs are lower considering your usage. But if you’re looking to do off-road trips or much driving outside the city where you need power to pull through, you’d want to invest on a diesel engine. Whatever you choose, the knowledge you have gained will help you know what is best for you. Happy shopping!