245/35R19 vs 305/25R20
305/25R20 is a safe swap for 245/35R19 by the usual ±3% rule: the diameter differs by +0.98%.
Speedometer and odometer
With 305/25R20 on a car calibrated for 245/35R19, 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 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 305/25R20?
305/25R20 is a safe swap for 245/35R19 by the usual ±3% rule: the diameter differs by +0.98%.
What's the difference between 245/35R19 and 305/25R20?
305/25R20 is 0.25" taller and 60 mm wider; the sidewall is -0.37". At an indicated 60 mph you'd actually be doing 60.6 mph.
Will 305/25R20 fit on 245/35R19 wheels?
No — 245/35R19 needs a 19" wheel and 305/25R20 a 20" wheel. This is a plus/minus-size swap that changes wheels too.