Should You Replace Two Tires or All Four at Once?

[VonAthena]

You can choose to replace either two tires or all four at once, but if conditions permit, it is recommended to replace all four tires simultaneously to maintain the original handling balance. Tires on the same axle should be of the same specification, structure, manufacturer, and tread pattern. If only two tires are being replaced, it is advisable to install the new tires on the rear wheels. If only one tire is being replaced, the new tire must have a tread groove depth similar to that of the other tire on the same axle; otherwise, it may cause issues such as vehicle pulling. Methods to determine whether tires need replacement are as follows: 1. Severe wear: Each tire tread groove has a wear limit indicator, which is approximately 2mm thick. It is recommended to replace the tires when the tread thickness wears to 4mm from the limit indicator, or about 6mm from the deepest part of the groove. 2. Severe aging: Observe the patterns on the tire tread and sidewalls. If cracks are widespread, it indicates severe tire aging. Even if the mileage is low or the usage time is short, the tires should be replaced promptly. Otherwise, the weakened sidewall strength of aged tires increases the risk of blowouts during high-speed driving due to rising temperatures. 3. Frequent repairs: One or two tire repairs will not affect tire usage, but after more than three repairs, it is recommended to replace the tires for safety reasons. During high-speed driving, the internal temperature of the tire rises, and although the damage has been repaired, the risk of failure still increases. 4. Bulging or deformation: Bulging or deformation of a tire is very dangerous. If such issues are found, it is best to have them inspected and handled by a professional repair shop immediately. In most cases, tire replacement is recommended. Such issues indicate that the internal metal coils of the tire have deformed or broken, and continuing to drive poses a high risk of blowouts. 5. Punctured sidewall: A punctured sidewall is indeed more dangerous than a damaged tread. If the damage is located below the indicator near the wheel rim edge, the tire must be replaced because the steel wire strength in this area is very weak, and the repair process will inevitably subject it to squeezing and deformation, making it difficult to ensure the repair's effectiveness.

[NolanDella]

When it comes to changing tires, I must share some safety tips from experience. Having driven for so many years, I've seen too many accidents caused by tire issues. If you only replace one tire, the significant wear difference between the new and old tires can cause the car to pull to one side and make braking unstable, especially in rainy or snowy conditions where traction is poor. It's best to replace a pair or all four new tires to ensure consistency on the same axle. For all-wheel-drive vehicles, special attention is needed as the differential could be damaged—manufacturers usually recommend replacing all tires. Checking wear is simple: use a tread depth gauge, and if the difference exceeds 2mm, replace a pair immediately. Regular tire rotation every 5,000 miles can also prevent uneven wear, but safe driving should always come first—don't risk big dangers to save small money.

[Isabel]

As a DIY car owner, budget is key when replacing tires. When money was tight, I once tried replacing just one damaged tire, only to face increased fuel consumption and constant pulling. I learned my lesson – now I always replace at least a pair of new tires on the drive axle: both front tires for FWD cars, or both rear tires for RWD. This provides better balance. If the old tires aren’t too worn, replacing just one pair can buy time, but check tread depth to avoid dangerous mismatches that cause skidding or suspension damage. Long-term, replacing all four tires is more convenient due to better matching, even wear, and fewer maintenance hassles. Always measure tread depth before deciding – never compromise safety.

[DelAlexa]

Last time I had a flat tire, I only replaced one. It felt fine at first, but after two months of driving, I noticed unstable handling. The mechanic said this would put stress on the suspension. Now I've replaced them in pairs—two new tires on the front axle and two on the rear—but made sure the tread patterns are similar, choosing the same brand and model to avoid issues. Safety is the top priority; even slight differences in wear can cause the car to lose control. Regular inspections and tire rotations can extend their lifespan.