Most drivers don't think about their spare tire until they need it — but understanding what type you have, its limitations, and how to use it can save you in a roadside emergency.
There are three main types: Full-size spare (same size as your regular tires — can be driven indefinitely if properly maintained), Temporary spare / "donut" (compact spare, typically 4 inches narrower — limited to 50 mph and 50–70 miles), and Run-flat tire (built-in reinforced sidewalls that allow limited driving — typically 50 mph for up to 50 miles — without needing a spare).
When using a compact spare: never exceed 50 mph, avoid extended highway use, do not use the spare to tow, and have your regular tire repaired or replaced as soon as possible. Compact spares are not designed for long-term use — driving on one significantly affects braking, ABS function, and stability control.
Your spare tire ages just like a regular tire, even if it's never been used. Check the spare's inflation pressure at least once a year (most full-size spares require 60 PSI; compact spares typically require 60 PSI as well). Also inspect the tread and sidewall for cracking or dry rot. A spare that's more than 10 years old should be replaced.
Many newer vehicles omit spare tires entirely to reduce weight, instead relying on run-flat tires or including a tire inflation kit (sealant and compressor). Know which type your vehicle has before you need it — a sealant kit cannot repair a sidewall blowout or a tear larger than about 6mm.
