175/65R14 vs 185/65R15 Tire Comparison
175/65R14 has nominal diameter 22.9567 in; 185/65R15 has 24.4685 in. Diameter changes 6.585%; at indicated 60 mph the new nominal speed is 63.951 mph. Selected standard passenger tire sizes, not a verified market-popularity ranking. Nominal dimensions do not guarantee vehicle fitment.
175/65R14 vs 185/65R15 Tire Comparison reference last updated · reference source
Loading calculator…
Dated static reference; no live data is fetched. Verify current source values and assumptions before relying on results.
What this tool does
175/65R14 has nominal diameter 22.9567 in; 185/65R15 has 24.4685 in. Diameter changes 6.585%; at indicated 60 mph the new nominal speed is 63.951 mph. Selected standard passenger tire sizes, not a verified market-popularity ranking. Nominal dimensions do not guarantee vehicle fitment.
How to use the 175/65R14 vs 185/65R15 Tire Comparison
- Check Tire width (mm): 175.
- Check Tire aspect ratio (%): 65.
- Check Tire rim diameter (inches): 14.
- Check Tire B width (mm): 185.
- Check Tire B aspect ratio (%): 65.
- Check Tire B rim diameter (inches): 15.
- Check Indicated speed (mph): 60.
- Review the 175/65R14 vs 185/65R15 Tire Comparison result and its exact-value comparison table.
- Verify assumptions before applying the result.
Formula
difference%=(diameterB/diameterA−1)×100; actual speed=indicated speed×diameterB/diameterA
- width
- Tire width (mm)
- aspect
- Tire aspect ratio (%)
- rim
- Tire rim diameter (inches)
- widthB
- Tire B width (mm)
- aspectB
- Tire B aspect ratio (%)
- rimB
- Tire B rim diameter (inches)
- speed
- Indicated speed (mph)
Assumes the speedometer was calibrated to the original tire. Does not check wheel offset, width or clearance.
Worked example
175/65R14 vs 185/65R15 Tire Comparison: Tire width (mm) = 175; Tire aspect ratio (%) = 65; Tire rim diameter (inches) = 14; Tire B width (mm) = 185; Tire B aspect ratio (%) = 65; Tire B rim diameter (inches) = 15; Indicated speed (mph) = 60. 175/65R14 has nominal diameter 22.9567 in; 185/65R15 has 24.4685 in. Diameter changes 6.585%; at indicated 60 mph the new nominal speed is 63.951 mph. Selected standard passenger tire sizes, not a verified market-popularity ranking. Nominal dimensions do not guarantee vehicle fitment.
Inputs
- Tire width (mm)175
- Tire aspect ratio (%)65
- Tire rim diameter (inches)14
- Tire B width (mm)185
- Tire B aspect ratio (%)65
- Tire B rim diameter (inches)15
- Indicated speed (mph)60
Result
- Diameter difference (%)6.59
- Actual speed (mph)63.95
- Ground clearance change0.76 in
175/65R14 versus 185/65R15
| Measurement | Original tire | New tire |
|---|---|---|
| Diameter (in) | 22.95669291338583 | 24.468503937007874 |
| Sidewall (in) | 4.478346456692914 | 4.734251968503937 |
| Circumference (in) | 72.12057780740979 | 76.87007221283687 |
| Revolutions/mile | 878.5287351578912 | 824.2479573138638 |
| Speed at indicated 30 mph | 30 | 31.975647401817866 |
| Speed at indicated 45 mph | 45 | 47.96347110272681 |
| Speed at indicated 60 mph | 60 | 63.95129480363573 |
| Speed at indicated 70 mph | 70 | 74.60984393757502 |
Results explained
- Diameter difference (%)
- Diameter difference (%) from the formula above. Assumes the speedometer was calibrated to the original tire. Does not check wheel offset, width or clearance.
- Actual speed (mph)
- Actual speed (mph) from the formula above. Assumes the speedometer was calibrated to the original tire. Does not check wheel offset, width or clearance.
- Ground clearance change
- Ground clearance change from the formula above, expressed in in before metric conversion. Assumes the speedometer was calibrated to the original tire. Does not check wheel offset, width or clearance.
Frequently asked questions
Diameter difference is 1.5118 inches (6.585%).
4.4783 and 4.7343 inches respectively.
Nominal actual speed becomes 63.951 mph if calibrated to 175/65R14.
878.53 versus 824.25 geometric revolutions/mile.
This comparison cannot confirm fitment. Ground clearance changes 0.7559055118110223 in geometrically; verify wheel width, offsets, load/speed ratings and manufacturer requirements.