295/30R20 vs 255/40R19
255/40R19 is a safe swap for 295/30R20 by the usual ±3% rule: the diameter differs by +0.23%.
Speedometer and odometer
With 255/40R19 on a car calibrated for 295/30R20, the speedometer reads 59.9 mph when you're really doing 60, and the odometer under-counts by 0.2%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 30.1 mph |
| 45 mph | 45.1 mph |
| 60 mph | 60.1 mph |
| 70 mph | 70.2 mph |
| 80 mph | 80.2 mph |
Other sizes close to 295/30R20
- 295/30R20 vs 245/40R19-0.93%
- 295/30R20 vs 245/40R20+2.77%
- 295/30R20 vs 245/35R20-0.80%
- 295/30R20 vs 255/35R20+0.22%
- 295/30R20 vs 275/35R20+2.26%
- 295/30R20 vs 255/40R20+3.94%
- 295/30R20 vs 225/45R19+0.01%
- 295/30R20 vs 285/35R19-0.42%
- 295/30R20 vs 285/35R20+3.28%
- 295/30R20 vs 285/30R20-0.88%
- 295/30R20 vs 275/30R20-1.75%
- 295/30R20 vs 265/35R20+1.24%
Questions
Can I replace 295/30R20 with 255/40R19?
255/40R19 is a safe swap for 295/30R20 by the usual ±3% rule: the diameter differs by +0.23%.
What's the difference between 295/30R20 and 255/40R19?
255/40R19 is 0.06" taller and 40 mm narrower; the sidewall is +0.53". At an indicated 60 mph you'd actually be doing 60.1 mph.
Will 255/40R19 fit on 295/30R20 wheels?
No — 295/30R20 needs a 20" wheel and 255/40R19 a 19" wheel. This is a plus/minus-size swap that changes wheels too.