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)?
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A175
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B65
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C14
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D82
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ES
Answer
Correct Answer: 65
Explanation
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:
Identify aspect ratio position after the slash.In 175/65 R14 82 S, the number after the slash is 65.Therefore, aspect ratio = 65% (sidewall height is 0.65 * 175 mm).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:
65