Final answer:
The question points to the significance of tire-replacement cost in U-Haul's equipment maintenance as a major business expense affecting vehicle reliability and safety.
Step-by-step explanation:
The statement "Tire-replacement cost is one of the largest expenses for U-Haul equipment maintenance" suggests that the maintenance of U-Haul's fleet of rental vehicles is a significant business expense, particularly due to the high cost associated with replacing tires. Maintenance costs are crucial for a rental company's operations as they directly impact the reliability and safety of the vehicles, and, by extension, customer satisfaction and the company's reputation. The emphasis on tire-replacement cost highlights the frequent use and wear and tear of U-Haul vehicles, as tires are among the most heavily used components and need to be replaced to maintain performance and safety standards.