What type of maintenance can significantly affect a vehicle's reliability?

Preventive maintenance plays a crucial role in ensuring a vehicle's reliability. This type of maintenance involves regular inspections and servicing aimed at preventing potential issues before they occur. Activities such as oil changes, brake inspections, tire rotations, and fluid replacements help to maintain optimal performance and minimize the risk of breakdowns. By addressing small problems before they escalate, preventive maintenance extends the life of the vehicle, enhances safety, and promotes smoother operation.

Other maintenance activities, such as cosmetic upgrades or seasonal changes, do not directly impact the mechanical reliability of a vehicle. While they may improve aesthetics or prepare the vehicle for different weather conditions, they do not contribute to the essential functioning and overall dependability of the engine and its components. Similarly, sales promotions are unrelated to maintenance practices and do not influence the operational reliability of a vehicle.