A temporary spare tire, commonly called a "donut," is designed for short-term use only. You should not drive on it for more than 70 miles or at speeds exceeding 50 mph. Its primary purpose is to get you to the nearest repair shop safely. Driving beyond these limits compromises vehicle handling, braking, and can lead to tire failure or damage to your car's drivetrain. The donut's smaller size and limited durability mean it's a temporary fix, not a long-term solution.
The 70-mile and 50-mph limits are set by manufacturers for critical safety reasons. A donut has a much thinner tread and a different construction than a standard tire. It's not built to handle the stresses of high-speed travel or long distances. Exceeding these limits generates excessive heat, which can cause the tire to fail catastrophically. Furthermore, the significant difference in diameter from your other tires can strain the differential (on RWD/AWD vehicles) and damage the anti-lock braking system (ABS) and traction control sensors.
You should immediately plan to have your flat tire repaired or replaced. The donut is not a substitute for a full-size tire. Your driving should be cautious and deliberate—avoid sharp turns, sudden braking, and rough roads. The goal is to get to a professional as soon as possible.
| Factor | Recommended Limit | Rationale |
|---|
| Maximum Distance | 50-70 miles | The tire's structural integrity is not designed for extended use; heat buildup becomes dangerous. |
| Maximum Speed | 50 mph | Higher speeds generate excessive heat and compromise stability due to the smaller size. |
| Tread Depth | Typically 5/32" or less | Significantly less than a new standard tire (10/32" or more), offering minimal grip. |
| Tire Pressure | Often 60 PSI | Much higher than standard tires (typically 30-35 PSI); must be checked immediately after installation. |
| Vehicle Systems at Risk | Differential, ABS, Traction Control | The size difference forces these systems to work incorrectly, potentially causing costly damage. |
