225/35R19 vs 315/30R18
315/30R18 is a safe swap for 225/35R19 by the usual ±3% rule: the diameter differs by +0.95%.
Speedometer and odometer
With 315/30R18 on a car calibrated for 225/35R19, the speedometer reads 59.4 mph when you're really doing 60, and the odometer under-counts by 1.0%.
| 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 | 80.8 mph |
Other sizes close to 225/35R19
- 225/35R19 vs 225/40R18-0.45%
- 225/35R19 vs 235/40R18+0.80%
- 225/35R19 vs 235/40R19+4.76%
- 225/35R19 vs 255/35R19+3.28%
- 225/35R19 vs 255/35R18-0.69%
- 225/35R19 vs 245/35R19+2.19%
- 225/35R19 vs 225/40R19+3.52%
- 225/35R19 vs 235/35R19+1.09%
- 225/35R19 vs 265/35R18+0.41%
- 225/35R19 vs 265/35R19+4.37%
- 225/35R19 vs 285/30R19+2.11%
- 225/35R19 vs 305/30R19+3.98%
Questions
Can I replace 225/35R19 with 315/30R18?
315/30R18 is a safe swap for 225/35R19 by the usual ±3% rule: the diameter differs by +0.95%.
What's the difference between 225/35R19 and 315/30R18?
315/30R18 is 0.24" taller and 90 mm wider; the sidewall is +0.62". At an indicated 60 mph you'd actually be doing 60.6 mph.
Will 315/30R18 fit on 225/35R19 wheels?
No — 225/35R19 needs a 19" wheel and 315/30R18 a 18" wheel. This is a plus/minus-size swap that changes wheels too.