235/50R18 vs 265/40R19
265/40R19 is a safe swap for 235/50R18 by the usual ±3% rule: the diameter differs by +0.35%.
Speedometer and odometer
With 265/40R19 on a car calibrated for 235/50R18, 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 | 45.2 mph |
| 60 mph | 60.2 mph |
| 70 mph | 70.2 mph |
| 80 mph | 80.3 mph |
Other sizes close to 235/50R18
- 235/50R18 vs 225/45R18-4.70%
- 235/50R18 vs 245/45R18-2.09%
- 235/50R18 vs 235/45R18-3.39%
- 235/50R18 vs 235/55R18+3.39%
- 235/50R18 vs 235/55R17-0.27%
- 235/50R18 vs 225/50R18-1.44%
- 235/50R18 vs 255/40R19-0.81%
- 235/50R18 vs 225/55R18+1.81%
- 235/50R18 vs 255/40R18-4.48%
- 235/50R18 vs 215/60R17-0.35%
- 235/50R18 vs 245/50R18+1.44%
- 235/50R18 vs 255/45R18-0.79%
Questions
Can I replace 235/50R18 with 265/40R19?
265/40R19 is a safe swap for 235/50R18 by the usual ±3% rule: the diameter differs by +0.35%.
What's the difference between 235/50R18 and 265/40R19?
265/40R19 is 0.09" taller and 30 mm wider; the sidewall is -0.45". At an indicated 60 mph you'd actually be doing 60.2 mph.
Will 265/40R19 fit on 235/50R18 wheels?
No — 235/50R18 needs a 18" wheel and 265/40R19 a 19" wheel. This is a plus/minus-size swap that changes wheels too.