245/35R19 vs 255/40R19
255/40R19 is outside the ±3% rule as a replacement for 245/35R19: the diameter differs by +4.97%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.
Speedometer and odometer
With 255/40R19 on a car calibrated for 245/35R19, the speedometer reads 57.2 mph when you're really doing 60, and the odometer under-counts by 5.0%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 31.5 mph |
| 45 mph | 47.2 mph |
| 60 mph | 63.0 mph |
| 70 mph | 73.5 mph |
| 80 mph | 84.0 mph |
Other sizes close to 245/35R19
- 245/35R19 vs 245/40R18-0.14%
- 245/35R19 vs 225/45R18+0.86%
- 245/35R19 vs 245/40R19+3.75%
- 245/35R19 vs 235/40R19+2.52%
- 245/35R19 vs 255/35R19+1.07%
- 245/35R19 vs 275/35R19+3.21%
- 245/35R19 vs 225/40R19+1.30%
- 245/35R19 vs 235/35R19-1.07%
- 245/35R19 vs 225/45R19+4.74%
- 245/35R19 vs 275/35R18-0.67%
- 245/35R19 vs 285/35R19+4.28%
- 245/35R19 vs 265/35R19+2.14%
Questions
Can I replace 245/35R19 with 255/40R19?
255/40R19 is outside the ±3% rule as a replacement for 245/35R19: the diameter differs by +4.97%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.
What's the difference between 245/35R19 and 255/40R19?
255/40R19 is 1.28" taller and 10 mm wider; the sidewall is +0.64". At an indicated 60 mph you'd actually be doing 63.0 mph.
Will 255/40R19 fit on 245/35R19 wheels?
Both use a 19" rim, so the wheel diameter matches; check the wheel's width range for a 255 mm tire and the fender clearance.