1. Sock Dimensions (Width and Length)

Width: All snow socks, regardless of size, have a width of 40 cm (except the 3XL, which may differ).
Length: The sock length changes depending on the size (XL, XXL, etc.).

2. Why do the socks appear to have the same width on different tires?

Tire dimensions include two important elements:

Tread width: This is the main number (e.g., 285 mm for 285/40R20).
285 mm = 28.5 cm
255 mm = 25.5 cm
Sidewall height: This is a percentage of the width (e.g., 40% for 285/40R20, 45% for 255/45R20). In both cases:
40% of 285 mm = 11.4 cm
45% of 255 mm = 11.4 cm

Thus, the sidewall height is the same in both cases.

3. Why is a different size required?

The technical reason a longer sock is needed for wider tires (e.g., 285/40R20) is that:

The sock grips tightly on the sides of the tire.
If the sock is not “loose” enough (longer), it can become difficult to remove after use.

For example:

An XL sock might work well for a 255/45R20 tire because it is narrower.
The same XL sock, however, would grip too tightly on a 285/40R20 tire, making the sock almost impossible to remove after use.

For this reason, an XXL sock is used for wider tires to make removal easier.

4. Conclusion

The customer correctly observed that the socks appear to have the same visual width but different sizes. This happens because the width remains constant for production reasons, while the length varies to fit the tire size.

This difference in length ensures that:

The sock does not grip excessively on the sides of wider tires.
The sock can be easily removed after use.

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