255/50R19 vs 295/40R20
295/40R20 is a safe swap for 255/50R19 by the usual ±3% rule: the diameter differs by +0.87%.
Speedometer and odometer
With 295/40R20 on a car calibrated for 255/50R19, the speedometer reads 59.5 mph when you're really doing 60, and the odometer under-counts by 0.9%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 30.3 mph |
| 45 mph | 45.4 mph |
| 60 mph | 60.5 mph |
| 70 mph | 70.6 mph |
| 80 mph | 80.7 mph |
Other sizes close to 255/50R19
- 255/50R19 vs 235/60R18+0.22%
- 255/50R19 vs 235/55R19+0.47%
- 255/50R19 vs 245/45R19-4.68%
- 255/50R19 vs 255/45R20-0.01%
- 255/50R19 vs 255/55R18+0.01%
- 255/50R19 vs 255/45R19-3.46%
- 255/50R19 vs 225/55R19-1.02%
- 255/50R19 vs 275/40R19-4.75%
- 255/50R19 vs 235/50R19-2.71%
- 255/50R19 vs 245/55R19+1.97%
- 255/50R19 vs 255/55R19+3.46%
- 255/50R19 vs 265/50R19+1.36%
Questions
Can I replace 255/50R19 with 295/40R20?
295/40R20 is a safe swap for 255/50R19 by the usual ±3% rule: the diameter differs by +0.87%.
What's the difference between 255/50R19 and 295/40R20?
295/40R20 is 0.25" taller and 40 mm wider; the sidewall is -0.37". At an indicated 60 mph you'd actually be doing 60.5 mph.
Will 295/40R20 fit on 255/50R19 wheels?
No — 255/50R19 needs a 19" wheel and 295/40R20 a 20" wheel. This is a plus/minus-size swap that changes wheels too.