195/50R16 vs 225/50R15
225/50R15 is a safe swap for 195/50R16 by the usual ±3% rule: the diameter differs by +0.76%.
Speedometer and odometer
With 225/50R15 on a car calibrated for 195/50R16, the speedometer reads 59.5 mph when you're really doing 60, and the odometer under-counts by 0.8%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 30.2 mph |
| 45 mph | 45.3 mph |
| 60 mph | 60.5 mph |
| 70 mph | 70.5 mph |
| 80 mph | 80.6 mph |
Other sizes close to 195/50R16
Questions
Can I replace 195/50R16 with 225/50R15?
225/50R15 is a safe swap for 195/50R16 by the usual ±3% rule: the diameter differs by +0.76%.
What's the difference between 195/50R16 and 225/50R15?
225/50R15 is 0.18" taller and 30 mm wider; the sidewall is +0.59". At an indicated 60 mph you'd actually be doing 60.5 mph.
Will 225/50R15 fit on 195/50R16 wheels?
No — 195/50R16 needs a 16" wheel and 225/50R15 a 15" wheel. This is a plus/minus-size swap that changes wheels too.