Bennett Mechanical Comprehension Practice Test 2025 – The Complete All-in-One Guide to Exam Success!

Differential gears play a crucial role in a vehicle’s ability to navigate turns smoothly. When a vehicle turns, the wheels on the outside of the turn need to travel a greater distance than the wheels on the inside. If all wheels were fixed to rotate at the same speed, this would create friction and cause the tires to skid or scrub rather than roll naturally along the road surface.

By allowing for different wheel speeds, differential gears enable each wheel to rotate at the appropriate speed for its side of the turn. This not only enhances the handling and stability of the vehicle but also minimizes tire wear. Tires that are forced to rotate at the same speed during turns may experience unnecessary abrasion and degradation, leading to a reduced lifespan and requiring more frequent replacements.

While other options touch on important aspects of vehicle operation, such as traction or braking, they do not directly explain why different wheel speeds are essential during turns. The differential's primary function is to ensure smooth and efficient turning motion, which is inherently linked to the preservation of tire health and performance.