The Similarity

The diesel and petrol engines that are used in most cars are highly similar. In essence, they are internal combustion engines that usually works using a 4-strokes cycle. In an internal combustion engine, the power cycle is made up of four phases: intake, compression, power and exhaust; thus it is called the 4-strokes cycle

1st Stroke: Intake Phase

During the intake phase, air is drawn into cylinder through the opening intake valve. This is cause by the vacuum that was created when the piston is drawn downwards.

2nd Stroke: Compression Phase

Next is the compression phase. During this phase, intake valve closes and the piston is drawn up, compressing the air with fuel.

3rd Stroke: Power Phase

At this point, the compressed mixture of fuel and air is ignited to cause an explosion. It is this explosion that causes the piston to be pushed downwards and drive the crankshaft to produce motion.

4th Stroke: Exhaust Phase

During this final phase, the exhaust valve will be opened and when the piston is being drawn up, it pushes the spent air-fuel mixture out of the cylinder through the exhaust valve, allowing a new cycle to begin.

The Differences

The main difference between diesel and petrol engines is that petrol engines usually use spark plugs to ignite the air-fuel mixture, while diesel engines rely solely on heavily compressed air. The temperature of the compressed air could be made to increase high enough to ignite the diesel fuel if the air is being compressed heavily enough.

Petrol Engine

Diesel Engine


Diesel is also considerably cheaper than petrol. However, this comes with a drawback. Diesel engines emit more noxious gases and CO2 per litre of fuel used than petrol-powered cars. Diesel engines also require more raw materials and money to manufacture as well.

This October help save the environment from the noxious fumes of diesel and save your wallet from the cost of the petrol. Book one of our selected cars and you can receive a $10 petrol voucher for every 2 days of bookings.

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