We all know the importance of making sure the tires on our car have the proper inflation pressure. But what about your vehicle's fifth tire? Spare tires are often forgotten about or overlooked when it comes to maintenance. With your everyday tires being tested by summer's heat and your winter / snow tires battling harsh road conditions in the colder months, it's important to make sure you maintain the spare.
During one of our driving school events, we checked the air pressure of each participant's spare tire. Below are some of the findings from our experiment:
- Mini-spare specifying 60 psi inflated to 43 psi (28% underinflated)
- Mini-spare specifying 60 psi inflated to 27 psi (55% underinflated)
- Mini-spare specifying 60 psi inflated to 24 psi (60% underinflated)
- Mini-spare specifying 60 psi inflated to 18 psi (70% underinflated)
- Mini-spare specifying 60 psi inflated to 4 psi (93% underinflated)
- Full-size spare specifying 33 psi inflated to 9 psi (73% underinflated)
Since tires require inflation pressure to provide load capacity, if any of these tires had been placed into service, they would have been underinflated and overloaded. Even if driven on underinflated for a short period of time, the heat generated would have permanently damaged the tire or failed while in use.
With holiday travel just around the corner, below are some tips to keep your spare tire ready when you need it.
- Learn how to install the spare on your vehicle before you have to. Confirm where the jack is in the vehicle and practice changing a tire.
- Check your vehicle’s owner's manual and the temporary spare's sidewall for instructions on proper use.
- Check the spare tire's air pressure with a pressure gauge monthly while checking all other tires on your vehicle.
- Always confirm the inflation pressure before use and ensure that your spare has the manufacturer recommended inflation.