225/50R15 vs 185/55R16
185/55R16 is a safe swap for 225/50R15 by the usual ±3% rule: the diameter differs by +0.64%.
Speedometer and odometer
With 185/55R16 on a car calibrated for 225/50R15, the speedometer reads 59.6 mph when you're really doing 60, and the odometer under-counts by 0.6%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 30.2 mph |
| 45 mph | 45.3 mph |
| 60 mph | 60.4 mph |
| 70 mph | 70.5 mph |
| 80 mph | 80.5 mph |
Other sizes close to 225/50R15
- 225/50R15 vs 195/65R15+4.70%
- 225/50R15 vs 185/65R15+2.56%
- 225/50R15 vs 185/60R15-0.50%
- 225/50R15 vs 195/60R15+1.49%
- 225/50R15 vs 205/50R16+0.89%
- 225/50R15 vs 175/65R15+0.41%
- 225/50R15 vs 205/50R15-3.30%
- 225/50R15 vs 195/50R16-0.76%
- 225/50R15 vs 195/55R15-1.73%
- 225/50R15 vs 205/60R15+3.47%
- 225/50R15 vs 185/55R15-3.55%
- 225/50R15 vs 175/70R14-0.89%
Questions
Can I replace 225/50R15 with 185/55R16?
185/55R16 is a safe swap for 225/50R15 by the usual ±3% rule: the diameter differs by +0.64%.
What's the difference between 225/50R15 and 185/55R16?
185/55R16 is 0.15" taller and 40 mm narrower; the sidewall is -0.42". At an indicated 60 mph you'd actually be doing 60.4 mph.
Will 185/55R16 fit on 225/50R15 wheels?
No — 225/50R15 needs a 15" wheel and 185/55R16 a 16" wheel. This is a plus/minus-size swap that changes wheels too.