255/35R19 vs 345/30R19
345/30R19 is outside the ±3% rule as a replacement for 255/35R19: the diameter differs by +4.31%, 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 255/35R19, the speedometer reads 57.5 mph when you're really doing 60, and the odometer under-counts by 4.3%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 31.3 mph |
| 45 mph | 46.9 mph |
| 60 mph | 62.6 mph |
| 70 mph | 73.0 mph |
| 80 mph | 83.4 mph |
Other sizes close to 255/35R19
- 255/35R19 vs 225/45R18-0.21%
- 255/35R19 vs 245/40R19+2.65%
- 255/35R19 vs 235/40R19+1.44%
- 255/35R19 vs 255/40R19+3.86%
- 255/35R19 vs 255/40R18+0.02%
- 255/35R19 vs 275/35R19+2.12%
- 255/35R19 vs 245/35R19-1.06%
- 255/35R19 vs 225/40R19+0.23%
- 255/35R19 vs 235/35R19-2.12%
- 255/35R19 vs 225/45R19+3.63%
- 255/35R19 vs 285/35R19+3.18%
- 255/35R19 vs 265/35R19+1.06%
Questions
Can I replace 255/35R19 with 345/30R19?
345/30R19 is outside the ±3% rule as a replacement for 255/35R19: the diameter differs by +4.31%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.
What's the difference between 255/35R19 and 345/30R19?
345/30R19 is 1.12" taller and 90 mm wider; the sidewall is +0.56". At an indicated 60 mph you'd actually be doing 62.6 mph.
Will 345/30R19 fit on 255/35R19 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.