ADI Vehicle Safety & Mechanics 1

Question 1

What is the minimum legal tread depth for car tyres in the UK?

Accepted Answer

1.6 mm across the central 75% of the width around the full circumference

Answer

The legal minimum tread depth for cars in the UK is 1.6 mm across the central three-quarters of the tread width around the entire circumference of the tyre.

Question 2

What does the engine management warning light (amber) indicate?

Accepted Answer

A fault has been detected in the engine management system that requires investigation

Answer

The amber engine management light (EML) indicates that the engine control unit has detected a fault; the vehicle may still be driven but should be inspected by a qualified mechanic.

Question 3

How often should tyre pressures be checked?

Accepted Answer

At least monthly and before any long journey

Answer

Tyre pressures should be checked monthly and before long journeys; under-inflated tyres cause increased fuel consumption, uneven wear and can overheat, potentially causing a blowout.

Question 4

Anti-lock braking system (ABS) is designed to:

Accepted Answer

Prevent wheel lock-up under heavy braking, maintaining steering control

Answer

ABS modulates brake pressure to prevent wheel lock-up, allowing the driver to steer while braking hard; it does not necessarily reduce stopping distance but maintains directional control.

Question 5

Which fluid level should be checked as part of routine vehicle safety before a long journey?

Accepted Answer

Engine oil, coolant, brake fluid, power steering fluid and screenwash

Answer

Before a long journey a driver should check all fluid levels: engine oil, coolant, brake fluid, power steering fluid (if applicable) and screenwash, as well as tyre pressures and lights.

UK ADI Theory Practice Test

UK ADI Theory Practice Test

ADI Vehicle Safety & Mechanics 1