Why are the front and rear tires of the BMW X5 different?

[IrisLee]

The design of the vehicle model requires the rear tires to be larger than the front ones to ensure the stability of the vehicle. Here is some knowledge about tire replacement principles: 1. Same specifications: Tires of different specifications have different outer diameters and section widths after inflation, which leads to uneven load distribution when mounted on the same axle. 2. Same structure: Since radial tires and bias tires have different carcass structures, their cushioning performance and circumferential deformation vary. Mixing these two types of tires on the same axle will result in uneven load distribution and inconsistent wear. 3. Same material: The material mainly refers to the carcass cord material. For example, all-steel radial tires and fiber radial tires have significant differences in carcass thickness, cord strength, and heat dissipation performance. Mixing them will affect performance.