Compact or temporary spare tires, often called “donuts,” are designed for limited, emergency use following a flat tire. These spares are generally smaller and lighter than standard tires, constructed with a thinner tread, and often inflated to a higher pressure. Full-size spares, matching the other tires on the vehicle, offer no mileage restrictions but are less common due to space and weight considerations.
Understanding the limitations of a spare tire is crucial for road safety. Exceeding recommended mileage and speed limits on a temporary spare can lead to tire failure, loss of vehicle control, and potentially dangerous situations. Historically, spares were full-size; the advent of smaller, temporary spares was driven by fuel efficiency concerns and vehicle design changes. These smaller spares save weight and space, leading to better gas mileage and more compact vehicle designs.
