Chapter 7 - Maintaining vehicle stability

Question 1

What are the commonest causes of skidding?

Answer 1

• driving too fast for the circumstances
• harsh acceleration
• excessive or sudden breaking
• coarse steering

Question 2

What can harsh acceleration cause?

Answer 2

Harsh acceleration can cause the wheels to spin, even at low speeds.

Question 3

What can excessing or sudden breaking cause?

Answer 3

In a car without ABS excessing breaking for the road conditions may cause skidding because the tyres lose their grip.

Question 4

What does coarse steering cause?

Answer 4

If you steer too sharply for the speed you will cause the vehicle to understeer or oversteer. This may break the tyre grip and the vehicle will then go into a skid.

Question 5

What happens when you drive top fast for the circumstances?

Answer 5

When surface grip is low, altering speed or direction can exceed the available grip, causing a skid.

Question 6

What is understeering?

Answer 6

Understeer is the tendency of a vehicle to turn less.

Question 7

In a front wheel drive car, you will increase understeer if you

Answer 7

• enter the bend too fast
• apply too much power in the bend
• steer too sharply.

Question 8

Name the active safety systems.

Answer 8

• ABS - Anti-lock braking system
• TCS - Traction control system
• ESP - Electronic stability programmes

Question 9

What are the key points of the Active Safety features? (ABS, TC, ESP)

Answer 9

• if you break too hard, ABS prevents the wheel from locking up.
• if you accelerate top harshly, traction control prevents the wheel from excessive spinning.
• if you steer too sharply, ESP can help prevent the resulting oversteer or understeer from developing into a skid.
• Never rely on active safety devices. Always drive in such a way that they are not necessary.