235/30R20 vs 245/35R19
245/35R19 is a safe swap for 235/30R20 by the usual ±3% rule: the diameter differs by +0.79%.
Speedometer and odometer
With 245/35R19 on a car calibrated for 235/30R20, the speedometer reads 59.5 mph when you're really doing 60, and the odometer under-counts by 0.8%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 30.2 mph |
| 45 mph | 45.4 mph |
| 60 mph | 60.5 mph |
| 70 mph | 70.6 mph |
| 80 mph | 80.6 mph |
Other sizes close to 235/30R20
- 235/30R20 vs 245/35R20+4.70%
- 235/30R20 vs 235/35R19-0.29%
- 235/30R20 vs 285/30R20+4.62%
- 235/30R20 vs 275/30R20+3.70%
- 235/30R20 vs 285/30R19+0.71%
- 235/30R20 vs 235/35R20+3.62%
- 235/30R20 vs 275/30R19-0.22%
- 235/30R20 vs 245/30R20+0.92%
- 235/30R20 vs 265/30R20+2.77%
- 235/30R20 vs 255/30R20+1.85%
- 235/30R20 vs 225/35R20+2.54%
- 235/30R20 vs 335/25R20+4.08%
Questions
Can I replace 235/30R20 with 245/35R19?
245/35R19 is a safe swap for 235/30R20 by the usual ±3% rule: the diameter differs by +0.79%.
What's the difference between 235/30R20 and 245/35R19?
245/35R19 is 0.20" taller and 10 mm wider; the sidewall is +0.60". At an indicated 60 mph you'd actually be doing 60.5 mph.
Will 245/35R19 fit on 235/30R20 wheels?
No — 235/30R20 needs a 20" wheel and 245/35R19 a 19" wheel. This is a plus/minus-size swap that changes wheels too.