295/30R19 vs 255/40R18
255/40R18 is a safe swap for 295/30R19 by the usual ±3% rule: the diameter differs by +0.24%.
Speedometer and odometer
With 255/40R18 on a car calibrated for 295/30R19, 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 295/30R19
- 295/30R19 vs 225/45R18+0.02%
- 295/30R19 vs 245/40R18-0.97%
- 295/30R19 vs 245/40R19+2.88%
- 295/30R19 vs 235/40R19+1.67%
- 295/30R19 vs 255/40R19+4.09%
- 295/30R19 vs 255/35R19+0.23%
- 295/30R19 vs 275/35R19+2.35%
- 295/30R19 vs 245/35R19-0.83%
- 295/30R19 vs 225/40R19+0.45%
- 295/30R19 vs 235/35R19-1.90%
- 295/30R19 vs 225/45R19+3.87%
- 295/30R19 vs 285/35R19+3.41%
Questions
Can I replace 295/30R19 with 255/40R18?
255/40R18 is a safe swap for 295/30R19 by the usual ±3% rule: the diameter differs by +0.24%.
What's the difference between 295/30R19 and 255/40R18?
255/40R18 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 255/40R18 fit on 295/30R19 wheels?
No — 295/30R19 needs a 19" wheel and 255/40R18 a 18" wheel. This is a plus/minus-size swap that changes wheels too.