Differentials — role during cornering and tyre life A differential allows the left and right drive wheels to rotate at different speeds when cornering. Evaluate the statement: “It ensures each wheel turns at a speed matching the distance it must travel around a corner and thereby helps prevent excessive tyre wear.”

Introduction / Context:
When a vehicle turns, the outer wheel traces a larger radius and must travel a longer path than the inner wheel. Without a differential, both wheels would be forced to rotate at the same speed, causing scrub, noise, and accelerated tyre wear. The differential solves this by splitting torque while permitting speed difference.

Given Data / Assumptions:

• Open (standard) differential on a dry, paved road.
• Steady-state cornering without wheel slip.
• Proper tyre inflation and alignment.

Concept / Approach:
An open differential maintains the average speed of the two wheels equal to the ring-gear speed while allowing each axle shaft to rotate at its own speed. This accommodates different path lengths and reduces lateral scrub forces that would otherwise grind rubber against asphalt, generating heat and wear.

Step-by-Step Solution:

Verification / Alternative check:
Vehicles with locked differentials or welded spiders show chirping/skipping in tight turns, a clear symptom of tyre scrub that the open differential is designed to avoid.

Why Other Options Are Wrong:

• Speed limits (e.g., below 20 km/h) do not define the principle; it works at all speeds.
• Limited-slip is not required to prevent wear in normal turns; it adds traction biasing.
• Applies to both FWD and RWD vehicles.

Common Pitfalls:
Confusing traction limitations of open differentials with their geometric function; assuming LSDs always improve tyre life (they can increase scrub in tight low-speed turns).

Final Answer: