Why is there water in the spare tire?

[StReese]

It indicates trunk leakage and should be inspected promptly. Definition of spare tire: A spare tire refers to the backup tire for a sedan, with specifications identical to the original car tires. However, some vehicles use specially colored wheel rims, compact spares, folding spares, or run-flat tires as spare tires to remind owners to inspect and replace faulty tires promptly. Classification of spare tires: Full-size spare tire: A full-size spare has identical specifications to the other four tires on the vehicle and can replace any temporarily or permanently unusable tire. Compact spare tire: This type of spare has slightly smaller diameter and width compared to the other four tires.