195/50R16 vs 245/45R16
245/45R16 is outside the ±3% rule as a replacement for 195/50R16: the diameter differs by +4.24%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.
Speedometer and odometer
With 245/45R16 on a car calibrated for 195/50R16, the speedometer reads 57.6 mph when you're really doing 60, and the odometer under-counts by 4.2%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 31.3 mph |
| 45 mph | 46.9 mph |
| 60 mph | 62.5 mph |
| 70 mph | 73.0 mph |
| 80 mph | 83.4 mph |
Other sizes close to 195/50R16
Questions
Can I replace 195/50R16 with 245/45R16?
245/45R16 is outside the ±3% rule as a replacement for 195/50R16: the diameter differs by +4.24%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.
What's the difference between 195/50R16 and 245/45R16?
245/45R16 is 1.00" taller and 50 mm wider; the sidewall is +0.50". At an indicated 60 mph you'd actually be doing 62.5 mph.
Will 245/45R16 fit on 195/50R16 wheels?
Both use a 16" rim, so the wheel diameter matches; check the wheel's width range for a 245 mm tire and the fender clearance.