285/35R19 vs 255/40R19
255/40R19 is a safe swap for 285/35R19 by the usual ±3% rule: the diameter differs by +0.66%.
Speedometer and odometer
With 255/40R19 on a car calibrated for 285/35R19, the speedometer reads 59.6 mph when you're really doing 60, and the odometer under-counts by 0.7%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 30.2 mph |
| 45 mph | 45.3 mph |
| 60 mph | 60.4 mph |
| 70 mph | 70.5 mph |
| 80 mph | 80.5 mph |
Other sizes close to 285/35R19
- 285/35R19 vs 245/45R18-0.65%
- 285/35R19 vs 245/45R19+3.08%
- 285/35R19 vs 245/40R19-0.51%
- 285/35R19 vs 225/50R18+0.01%
- 285/35R19 vs 235/40R19-1.69%
- 285/35R19 vs 255/35R19-3.08%
- 285/35R19 vs 255/45R19+4.40%
- 285/35R19 vs 275/35R19-1.03%
- 285/35R19 vs 275/40R19+3.01%
- 285/35R19 vs 245/35R20-0.38%
- 285/35R19 vs 245/35R19-4.10%
- 285/35R19 vs 255/35R20+0.65%
Questions
Can I replace 285/35R19 with 255/40R19?
255/40R19 is a safe swap for 285/35R19 by the usual ±3% rule: the diameter differs by +0.66%.
What's the difference between 285/35R19 and 255/40R19?
255/40R19 is 0.18" taller and 30 mm narrower; the sidewall is +0.09". At an indicated 60 mph you'd actually be doing 60.4 mph.
Will 255/40R19 fit on 285/35R19 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.