So you know you need a new tire, or maybe two, but what if an auto technician tells you to replace tires you thought were still good? While there are certainly parameters in place for when a tire needs to be replaced, sometimes knowing how many to replace can be a little trickier.
While it may seem logical that if you have a tire blowout, you just need to replace that 1 tire, you may actually need to replace the others as well. Why is that? It’s usually dependent on the vehicle itself and the remaining tread depths on the other tires.
The general rule of thumb is that it’s ok to replace just 1 tire at a time if the other tires have 8/32nds or more of tread depth left. Most new tires come with anywhere from 9/32nds – 11/32nds of an inch of tread depth (winter tires usually have more and summer tires usually have less). With that in mind, 8/32nds is still relatively new tread, so the difference between that tire and a brand-new tire isn’t so big. If there is a greater difference in tread depth between tires, you run the risk of the tires wearing unevenly, as well as unpredictable handling and traction. (Click here to learn how to measure your tread depth.) If your existing tires have less than 8/32nds of tread depth left, the recommended tires to replace are dependent on the vehicle type as follows:
On AWD Vehicles
It’s always best to replace all 4 tires at the same time. This is because all 4 tires spin independently of one another, and different tread depths and/or styles can cause them to spin at different speeds. That could potentially damage the drive train, and possibly affect an indirect TPMS system if the vehicle has one. (Indirect TPMS tells you the air pressure of the tires based on how fast the wheels spin.) While indirect TPMS can be reset by a professional, you definitely don’t want to cause damage to the drive train of your vehicle!
On 2WD Vehicles
It’s ideal to replace in at least pairs – tires on the same axle. While 2WD vehicles won’t necessarily be damaged by differing tread depths, you’ll still get much more even tread wear and more predictable handling and traction if each axle has matching tires. Of course, the ideal situation would be to replace all tires together, but if that’s not possible, consider replacing in pairs.
The next time you need a new tire, take a close look at the others and remember these rules. Your vehicle is only as safe as your tires! If you’re unsure about how many should be replaced, it’s never a bad idea to have a professional inspect them. Stop in to any of Wiygul Automotive Clinic’s 7 locations and our tire techs will be happy to inspect your tires and replace them with care and precision!