225/40R19 vs 345/30R19
345/30R19 is outside the ±3% rule as a replacement for 225/40R19: the diameter differs by +4.07%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.
Speedometer and odometer
With 345/30R19 on a car calibrated for 225/40R19, the speedometer reads 57.7 mph when you're really doing 60, and the odometer under-counts by 4.1%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 31.2 mph |
| 45 mph | 46.8 mph |
| 60 mph | 62.4 mph |
| 70 mph | 72.9 mph |
| 80 mph | 83.3 mph |
Other sizes close to 225/40R19
- 225/40R19 vs 225/45R18-0.44%
- 225/40R19 vs 235/45R18+0.92%
- 225/40R19 vs 245/40R19+2.41%
- 225/40R19 vs 235/40R19+1.21%
- 225/40R19 vs 255/40R19+3.62%
- 225/40R19 vs 255/35R19-0.23%
- 225/40R19 vs 255/40R18-0.21%
- 225/40R19 vs 275/35R19+1.89%
- 225/40R19 vs 245/35R19-1.28%
- 225/40R19 vs 235/35R19-2.34%
- 225/40R19 vs 225/45R19+3.40%
- 225/40R19 vs 285/35R19+2.94%
Questions
Can I replace 225/40R19 with 345/30R19?
345/30R19 is outside the ±3% rule as a replacement for 225/40R19: the diameter differs by +4.07%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.
What's the difference between 225/40R19 and 345/30R19?
345/30R19 is 1.06" taller and 120 mm wider; the sidewall is +0.53". At an indicated 60 mph you'd actually be doing 62.4 mph.
Will 345/30R19 fit on 225/40R19 wheels?
Both use a 19" rim, so the wheel diameter matches; check the wheel's width range for a 345 mm tire and the fender clearance.