235/50R19 vs 235/45R20
235/45R20 is a safe swap for 235/50R19 by the usual ±3% rule: the diameter differs by +0.26%.
Speedometer and odometer
With 235/45R20 on a car calibrated for 235/50R19, the speedometer reads 59.8 mph when you're really doing 60, and the odometer under-counts by 0.3%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 30.1 mph |
| 45 mph | 45.1 mph |
| 60 mph | 60.2 mph |
| 70 mph | 70.2 mph |
| 80 mph | 80.2 mph |
Other sizes close to 235/50R19
- 235/50R19 vs 235/55R19+3.27%
- 235/50R19 vs 235/55R18-0.26%
- 235/50R19 vs 245/45R19-2.02%
- 235/50R19 vs 255/50R19+2.79%
- 235/50R19 vs 255/40R19-4.32%
- 235/50R19 vs 255/45R19-0.77%
- 235/50R19 vs 225/55R19+1.74%
- 235/50R19 vs 275/40R19-2.09%
- 235/50R19 vs 255/40R20-0.78%
- 235/50R19 vs 225/45R19-4.53%
- 235/50R19 vs 245/55R19+4.81%
- 235/50R19 vs 285/35R19-4.95%
Questions
Can I replace 235/50R19 with 235/45R20?
235/45R20 is a safe swap for 235/50R19 by the usual ±3% rule: the diameter differs by +0.26%.
What's the difference between 235/50R19 and 235/45R20?
235/45R20 is 0.07" taller and 0 mm wider; the sidewall is -0.46". At an indicated 60 mph you'd actually be doing 60.2 mph.
Will 235/45R20 fit on 235/50R19 wheels?
No — 235/50R19 needs a 19" wheel and 235/45R20 a 20" wheel. This is a plus/minus-size swap that changes wheels too.