235/55R18 vs 235/50R19
235/50R19 is a safe swap for 235/55R18 by the usual ±3% rule: the diameter differs by +0.27%.
Speedometer and odometer
With 235/50R19 on a car calibrated for 235/55R18, 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 235/55R18
- 235/55R18 vs 235/60R18+3.28%
- 235/55R18 vs 235/50R18-3.28%
- 235/55R18 vs 225/60R18+1.61%
- 235/55R18 vs 225/50R18-4.68%
- 235/55R18 vs 245/60R18+4.96%
- 235/55R18 vs 225/55R18-1.54%
- 235/55R18 vs 255/55R18+3.07%
- 235/55R18 vs 255/45R19-0.50%
- 235/55R18 vs 235/60R17-0.27%
- 235/55R18 vs 215/65R17-0.61%
- 235/55R18 vs 245/50R18-1.89%
- 235/55R18 vs 255/45R18-4.05%
Questions
Can I replace 235/55R18 with 235/50R19?
235/50R19 is a safe swap for 235/55R18 by the usual ±3% rule: the diameter differs by +0.27%.
What's the difference between 235/55R18 and 235/50R19?
235/50R19 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 235/50R19 fit on 235/55R18 wheels?
No — 235/55R18 needs a 18" wheel and 235/50R19 a 19" wheel. This is a plus/minus-size swap that changes wheels too.