255/35R19 vs 235/40R19
235/40R19 is a safe swap for 255/35R19 by the usual ±3% rule: the diameter differs by +1.44%.
Speedometer and odometer
With 235/40R19 on a car calibrated for 255/35R19, the speedometer reads 59.2 mph when you're really doing 60, and the odometer under-counts by 1.4%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 30.4 mph |
| 45 mph | 45.6 mph |
| 60 mph | 60.9 mph |
| 70 mph | 71.0 mph |
| 80 mph | 81.1 mph |
Other sizes close to 255/35R19
- 255/35R19 vs 225/45R18-0.21%
- 255/35R19 vs 245/40R19+2.65%
- 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%
- 255/35R19 vs 235/45R19+4.99%
Questions
Can I replace 255/35R19 with 235/40R19?
235/40R19 is a safe swap for 255/35R19 by the usual ±3% rule: the diameter differs by +1.44%.
What's the difference between 255/35R19 and 235/40R19?
235/40R19 is 0.37" taller and 20 mm narrower; the sidewall is +0.19". At an indicated 60 mph you'd actually be doing 60.9 mph.
Will 235/40R19 fit on 255/35R19 wheels?
Both use a 19" rim, so the wheel diameter matches; check the wheel's width range for a 235 mm tire and the fender clearance.