What are the four strokes of a petrol engine?

Induction (intake), compression, power (combustion) and exhaust, in that order, often remembered as suck, squeeze, bang, blow. Both valves are closed during the compression and power strokes, and only the power stroke produces useful work.

What is the difference between the cooling system and the lubrication system?

The cooling system (water pump, thermostat, radiator, fan and coolant) removes the engine's waste combustion heat to stop it overheating. The lubrication system (sump, oil pump and oil filter) circulates oil to reduce friction between moving parts, and the oil also helps cool, clean, seal and protect against corrosion.

What does the ignition coil do?

The ignition coil steps up the battery's low voltage (about 12 V) to the thousands of volts needed to make a spark jump the spark plug gap. The high-voltage pulse is delivered to the correct cylinder at the correct time by a distributor (older cars) or electronic ignition (modern cars).

What do the clutch and gearbox do?

The clutch connects and disconnects the engine from the gearbox so the driver can move off smoothly and change gear. The gearbox provides gear ratios - low gears give more turning force for moving off and hills, high gears let the car cruise at speed with the engine turning slowly - plus neutral and reverse.

What is the legal minimum tyre tread depth?

1.6 mm across the central three-quarters of the tyre and around its whole circumference. Tread clears water to keep grip and avoid aquaplaning, and tyres must also be correctly inflated for grip, braking, even wear and economy.

Northern IrelandMotor Vehicle & Road User Studies

The motor vehicle: engine and systems - CCEA GCSE MVRUS study guide

A CCEA GCSE Motor Vehicle and Road User Studies study guide to vehicle engineering: the four-stroke engine, fuel, cooling, lubrication and ignition systems, the transmission, braking, tyres, steering and suspension, and routine maintenance.

Generated by Claude Opus 4.810 min readCCEAUpdated 2026-06-15

Reviewed by: AI editorial process; not yet individually human-reviewed

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What this module covers
How the topics fit together
How it is assessed
How to revise this module

What this module covers

This module is the vehicle engineering part of CCEA GCSE Motor Vehicle and Road User Studies (MVRUS), examined in Unit 1: Motor Vehicle and Road Use Theory. It explains how a car works system by system: the engine and its four-stroke cycle, the fuel, cooling, lubrication and ignition systems that keep it running, and the transmission, brakes, tyres, steering and suspension that control the car, plus the maintenance that keeps it safe.

How the topics fit together

The four-stroke petrol engine cycle - induction, compression, power and exhaust, the valves and the main engine parts.
The fuel system and combustion - tank, pump, filter and the air-fuel mixture from a carburettor or fuel injection, plus the exhaust.
The engine cooling system - radiator, water pump, thermostat, fan and coolant, and antifreeze.
Engine lubrication and the oil system - the functions of oil and the sump, oil pump and oil filter.
The ignition and electrical system - battery, alternator, starter motor and the coil and spark plugs.
The transmission system - clutch, gearbox, drive shaft and differential.
The braking system - hydraulic brakes, disc and drum brakes, the handbrake and ABS.
Tyres, steering and suspension - grip, tread and pressure, the steering and the suspension.
Vehicle maintenance and safety checks - routine checks, servicing and roadworthiness.

How it is assessed

Unit 1 is a written paper. Expect to:

Name the four strokes and the valve positions, and label engine parts.
Explain each system (cooling, lubrication, ignition, fuel) and the job of named parts (thermostat, coil, oil filter, clutch, differential).
Compare disc and drum brakes and explain ABS.
State the 1.6 mm tyre limit and list routine checks.

How to revise this module

Drill the four strokes ("suck, squeeze, bang, blow") and which strokes seal the cylinder.
Learn each system as "parts plus what they do", focusing on the parts named in past papers (thermostat, coil, clutch, differential, oil filter).
Be ready to use friction turns kinetic energy into heat to explain braking.
Memorise the 1.6 mm tread limit and the FLOWERY routine checks.
Practise short engine calculations such as engine capacity.

Sources & how we know this

CCEA GCSE Motor Vehicle and Road User Studies specification — CCEA (2017)