Do I Need to Replace Two Tires at the Same Time?
4 Answers
It is not necessary to replace two tires at the same time. The specific situations can be divided into the following: 1. If it is a new car and the mileage is not high, you only need to replace the problematic tire because the wear difference between tires on the same axle is not significant; 2. If the vehicle has already traveled tens of thousands of kilometers but does not yet require tire replacement, and only one tire has an issue, replacing just one tire may cause uneven height, leading to vehicle bumpiness or steering deviation at higher speeds. In this case, it is best to replace a pair of tires; 3. If the repair shop does not have the same brand or model of tire for the vehicle, replacing a pair is necessary for short-term driving, while replacing two pairs is required for long-term driving.
I've been repairing cars for over a decade and seen this issue many times. Whether tires need to be replaced in pairs depends on wear conditions. If the other tire on the same axle is worn down to just 2mm tread depth, replacing only one tire will create unbalanced grip between sides, making the car prone to skidding or fishtailing during braking. This is especially critical for front tires on front-wheel drive vehicles or rear tires on rear-wheel drive cars - if the tread depth difference exceeds 1.5mm between sides, it may affect steering and water drainage performance. Last week, a regular customer who replaced just one front tire nearly lost control when cornering in the rain. I recommend using a tread depth gauge to measure old tires - if they're more than halfway worn, replace them as a pair. Remember to install new tires on the drive wheels for more stable steering. As a side note, for all-wheel drive vehicles, it's best to replace all four tires simultaneously to avoid potential drivetrain damage.
Last month, I had a nail puncture in my left front tire and initially planned to replace just that one. The experienced mechanic at the shop spent quite some time measuring with calipers and told me my right front tire had already run 50,000 kilometers, with the tread worn close to the safety limit. He explained that the two front tires are like shoes on your feet—wearing one new and one old would definitely make walking awkward. Especially when driving through puddles at high speeds, the difference in drainage between new and old tires can easily cause skidding. In the end, I took his advice and replaced both front tires together. Sure enough, the braking no longer pulls to the left. If the other three tires are still relatively new, it's fine to replace just one, but remember to choose the same brand and model for the rear tire. Car maintenance should always prioritize safety—don't risk big trouble to save small money.
Tire symmetry and balance are crucial! When driving, the tires on both sides of the same axle must maintain similar conditions. Replacing only one side can cause differences in grip and elasticity between new and old tires, making the steering feel unstable—especially dangerous during emergency maneuvers. Last week on the highway, I learned this the hard way—the new right tire kept pulling the car to the right. Now, I use a one-yuan coin to check tread depth: if the coin inserted into the tread doesn’t expose the text, it’s still good. Before replacing tires, check the wear level of the old ones—if it exceeds 50%, replace both. Of course, if a tire replaced just six months ago gets punctured, replacing just one is acceptable. Remember, always install new tires on the rear axle—even for front-wheel-drive cars, it’s safer this way.
