You never know when you’ll need to use your spare tire! A little preventive maintenance can play dividends when they’re needed.
If a compact spare tire has been tucked into a cargo floor for several years, there is a good chance it is severely underinflated. It may be unable to handle the load and stress of emergency road duty. Compact spares should be inflated to 60 pounds per square inch- anything less could damage the wheel. A “doughnut” spare is designed for only temporary use, though, typically up to 100 miles max. A vehicle owner should check the spare tire at least twice a year. If your spare is mounted to your liftgate or under the cargo area, dirt, salt, water, and snow can cause corrosion to your mounting hardware. Periodic inspection, and cleaning, can make it easier to remove the spare when needed.
If your vehicle has a tire inflator kit instead of a spare tire, you could run into different issues. The sealant may not be able to seal all punctures. Also the sealant that gets injected into the tire probably has an expiration date. The sealant might not work as well after that date, so it should be replaced.
Finally, keep a large plastic trash bag in your vehicle. This will allow you to transport a flat tire without dirtying the trunk, or potentially, the cabin.