245/35R19 vs 245/30R20
245/30R20 is a safe swap for 245/35R19 by the usual ±3% rule: the diameter differs by +0.14%.
Speedometer and odometer
With 245/30R20 on a car calibrated for 245/35R19, the speedometer reads 59.9 mph when you're really doing 60, and the odometer under-counts by 0.1%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 30.0 mph |
| 45 mph | 45.1 mph |
| 60 mph | 60.1 mph |
| 70 mph | 70.1 mph |
| 80 mph | 80.1 mph |
Other sizes close to 245/35R19
- 245/35R19 vs 245/40R18-0.14%
- 245/35R19 vs 225/45R18+0.86%
- 245/35R19 vs 245/40R19+3.75%
- 245/35R19 vs 235/40R19+2.52%
- 245/35R19 vs 255/40R19+4.97%
- 245/35R19 vs 255/35R19+1.07%
- 245/35R19 vs 275/35R19+3.21%
- 245/35R19 vs 225/40R19+1.30%
- 245/35R19 vs 235/35R19-1.07%
- 245/35R19 vs 225/45R19+4.74%
- 245/35R19 vs 275/35R18-0.67%
- 245/35R19 vs 285/35R19+4.28%
Questions
Can I replace 245/35R19 with 245/30R20?
245/30R20 is a safe swap for 245/35R19 by the usual ±3% rule: the diameter differs by +0.14%.
What's the difference between 245/35R19 and 245/30R20?
245/30R20 is 0.04" taller and 0 mm wider; the sidewall is -0.48". At an indicated 60 mph you'd actually be doing 60.1 mph.
Will 245/30R20 fit on 245/35R19 wheels?
No — 245/35R19 needs a 19" wheel and 245/30R20 a 20" wheel. This is a plus/minus-size swap that changes wheels too.