225/40R19 vs 315/30R19
315/30R19 is a safe swap for 225/40R19 by the usual ±3% rule: the diameter differs by +1.36%.
Speedometer and odometer
With 315/30R19 on a car calibrated for 225/40R19, 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 | 60.8 mph |
| 70 mph | 71.0 mph |
| 80 mph | 81.1 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 315/30R19?
315/30R19 is a safe swap for 225/40R19 by the usual ±3% rule: the diameter differs by +1.36%.
What's the difference between 225/40R19 and 315/30R19?
315/30R19 is 0.35" taller and 90 mm wider; the sidewall is +0.18". At an indicated 60 mph you'd actually be doing 60.8 mph.
Will 315/30R19 fit on 225/40R19 wheels?
Both use a 19" rim, so the wheel diameter matches; check the wheel's width range for a 315 mm tire and the fender clearance.