Spare tyre pressure, including space-savers

A matching full-size spare is a fifth road tyre. Set it to the higher of the two axle placard numbers and check it when you check the other four.

A compact temporary spare has its own number, commonly around 60 psi (4.1 bar). That number is on the spare’s sidewall. Speed and distance limits (often 50 mph, a few dozen miles) still apply.

Some cars carry a folding spare that inflates from a canister. Follow that kit. Do not treat 4.1 bar as universal if the label says otherwise.

Inflator-and-sealant kits replace the spare on many EVs. Check the sealant date. Practice finding the kit before a rainstorm at night.

After you use a space-saver, repair the road tyre and put the compact back at its high pressure. Do not leave a 4.1 bar spare in the boot at 2.3 bar because you topped it from the same hose.