285/30R19 vs 225/45R18
225/45R18 is a safe swap for 285/30R19 by the usual ±3% rule: the diameter differs by +0.93%.
Speedometer and odometer
With 225/45R18 on a car calibrated for 285/30R19, the speedometer reads 59.4 mph when you're really doing 60, and the odometer under-counts by 0.9%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 30.3 mph |
| 45 mph | 45.4 mph |
| 60 mph | 60.6 mph |
| 70 mph | 70.7 mph |
| 80 mph | 80.7 mph |
Other sizes close to 285/30R19
- 285/30R19 vs 245/40R18-0.06%
- 285/30R19 vs 245/40R19+3.82%
- 285/30R19 vs 235/40R19+2.60%
- 285/30R19 vs 255/35R19+1.15%
- 285/30R19 vs 275/35R19+3.29%
- 285/30R19 vs 245/35R19+0.08%
- 285/30R19 vs 225/40R19+1.38%
- 285/30R19 vs 235/35R19-0.99%
- 285/30R19 vs 225/45R19+4.82%
- 285/30R19 vs 275/35R18-0.60%
- 285/30R19 vs 285/35R19+4.36%
- 285/30R19 vs 265/35R19+2.22%
Questions
Can I replace 285/30R19 with 225/45R18?
225/45R18 is a safe swap for 285/30R19 by the usual ±3% rule: the diameter differs by +0.93%.
What's the difference between 285/30R19 and 225/45R18?
225/45R18 is 0.24" taller and 60 mm narrower; the sidewall is +0.62". At an indicated 60 mph you'd actually be doing 60.6 mph.
Will 225/45R18 fit on 285/30R19 wheels?
No — 285/30R19 needs a 19" wheel and 225/45R18 a 18" wheel. This is a plus/minus-size swap that changes wheels too.