Can the front and rear tires of a 4WD vehicle be different sizes?
2 Answers
4WD vehicles cannot have front and rear tires of different sizes. If the original four tires are of the same specification and are replaced with two front tires of one size and two rear tires of another, it will affect the vehicle. Consequences of different front and rear tires: Because the front and rear axle tires have different specifications, it can result in different grip levels or different outer diameters, leading to handling or mechanical issues. Full-time 4WD tire replacement precautions: A major precaution for full-time 4WD vehicles is to avoid replacing just one tire on the same axle, as this can cause uneven tread patterns on either side of the vehicle, increasing driving hazards. For full-time 4WD vehicles, it is best to replace all four tires at once, though some may opt to replace only the two tires on the same axle.
I've been driving four-wheel-drive vehicles for over a decade and once experienced having tires of different sizes on the front and rear. That time, I only replaced the front tires with ones slightly larger than the rear. The car felt shaky when driving, and at higher speeds, it became noticeably unstable. Later, when I took it for repairs, the mechanic explained that four-wheel-drive systems require all wheels to rotate at the same speed. Having tires of different sizes causes additional friction in the differential, damaging the drivetrain components, and the repair cost me several thousand dollars. Since then, I've insisted on keeping the front and rear tires completely identical in size and tread pattern, including ensuring the rolling radius difference doesn't exceed 1%. This experience taught me that saving money temporarily can lead to long-term problems. Now, every time I change tires, I check the old tire records to ensure everything meets the standards to avoid risks.
