Tyre size nomenclature For a tyre designated 175/65 R14 82 S, what is the aspect ratio (section height as a percentage of section width)?

Introduction / Context:
Tyre markings encode key parameters that affect ride, handling, and speed capability. The aspect ratio tells how tall the sidewall is relative to the tread width.

Given Data / Assumptions:

• Example marking: 175/65 R14 82 S.
• Conventional passenger tyre notation: width/aspect construction rim load index speed symbol.

Concept / Approach:
In the code 175/65 R14 82 S: 175 = section width in mm; 65 = aspect ratio (%); R = radial construction; 14 = rim diameter in inches; 82 = load index; S = speed rating.

Step-by-Step Solution:

Verification / Alternative check:
Any tyre data sheet or sidewall legend uses this standard notation across brands.

Why Other Options Are Wrong:

• 175: section width in mm.
• 14: rim diameter in inches.
• 82: load index (maximum load capacity code).
• S: speed symbol, not a dimension.

Common Pitfalls:
Confusing load index and speed symbol with dimensional parameters; forgetting that aspect ratio is a percent, not millimetres.

Final Answer: