Difference between Petrol and Diesel Engine

Petrol engines and Diesel engines were created for specific type of reasons. While diesel cars where manufactured for bigger vehicles like lorries and trucks, petrol cars were created for power cars like sedans and SUVs. Here are the different between petrol engines and Diesel engines

The difference is that Diesel engine is CI ( compression Ignition ) and petrol is SI ( Spark Ignition).

In petrol engines the mixture of air and petrol is drawn in by the falling piston.

In diesel engines only air is drawn in by the falling piston

In petrol engine, the mixture is compressed upto about 1/8th to 1/12th of its original size.

In diesel engine, only air is compressed upto about 1/14th to 1/25th of its original size.

In petrol engine, the air and fuel mixture is ignited using a spark plug and burns expanding and forcing the piston down.

In diesel engine, fuel is injected at a high pressure into the hot, compressed air in the cylinder, causing it to burn and force the piston down. No spark is required.

Petrol Engine is lighter in construction because it requires lighter flywheel.

Petrol engines need less maintenance and also cheaper compared to diesels .

Disel engine has higher compression ratio/it is more efficent,and dissel as a fuel mid more cheeper as compaired to patrol.

Petrol gives more power as compaier to dissel engine / but it is costy

Petrol destroys lubrication and burns the engine whereas diesel doesnt. So a diesel engine would last longer than a petrol engine.

Petrol engines are lighter than diesel engines.

A diesel engine would pull heavy loads easily than a petrol engine.

The diesel engine would be steady and carry heavier loads to longer distances.

Diesel engines have better fuel efficiency as compared to petrol due to the fact that they have higher compression ratio.

Diesel engines dont need an ignition system, which reduces their complexity. But they are more noisy and may require frequent maintenance as compared to petrol engines. Also they are more durable.

Diesel engines may also need glow plugs in extreme cold conditions which heat up the cylinder so that a cold engine can start easily.

Diesel engines give better mileage than petrol engines.diesel is much cheaper than petrol.