Understanding Petrol and Diesel Engines

What is the primary difference in the combustion process between petrol and diesel engines?

• Both use only compression ignition.

• Both use only spark ignition.

• Diesel engines use compression ignition, while petrol engines use spark ignition.

• Petrol engines use compression ignition, while diesel engines use spark ignition.

What component do diesel engines lack that is common in petrol engines?

• Valves

• Crankshaft

• Pistons

• Spark plugs

What is the term used to describe the initial combustion process in a diesel engine?

• Controlled combustion

• Deflagration

• Ignition delay

• Compression ignition

Why do diesel engines typically have lower maximum RPMs compared to petrol engines?

• Lighter engine internals

• Higher combustion pressures

• Lower air compression

• Faster ignition process

What is the role of the spark plug in a petrol engine?

• To inject fuel into the cylinder

• To compress the air in the cylinder

• To initiate the combustion process

• To cool down the engine

Which type of engine typically features a higher compression ratio?

• Neither, as compression does not vary by engine type

• Petrol engine

• Diesel engine

• Both have similar compression ratios

What is the main reason diesel engines are considered more fuel efficient than petrol engines?

• Higher compression ratios

• Lighter engine components

• Higher RPM capabilities

• Use of spark plugs

What is the effect of 'knock' in petrol engines?

• It decreases combustion temperatures.

• It increases fuel efficiency.

• It can destroy the engine over time.

• It stabilizes the combustion process.