275/35R19 vs 285/30R20
285/30R20 is a safe swap for 275/35R19 by the usual ±3% rule: the diameter differs by +0.58%.
Speedometer and odometer
With 285/30R20 on a car calibrated for 275/35R19, the speedometer reads 59.7 mph when you're really doing 60, and the odometer under-counts by 0.6%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 30.2 mph |
| 45 mph | 45.3 mph |
| 60 mph | 60.3 mph |
| 70 mph | 70.4 mph |
| 80 mph | 80.5 mph |
Other sizes close to 275/35R19
- 275/35R19 vs 245/45R18+0.39%
- 275/35R19 vs 235/45R18-0.95%
- 275/35R19 vs 245/45R19+4.15%
- 275/35R19 vs 245/40R19+0.52%
- 275/35R19 vs 235/40R19-0.67%
- 275/35R19 vs 255/40R19+1.70%
- 275/35R19 vs 255/35R19-2.07%
- 275/35R19 vs 275/40R19+4.07%
- 275/35R19 vs 245/35R20+0.65%
- 275/35R19 vs 245/35R19-3.11%
- 275/35R19 vs 225/40R19-1.85%
- 275/35R19 vs 235/35R19-4.15%
Questions
Can I replace 275/35R19 with 285/30R20?
285/30R20 is a safe swap for 275/35R19 by the usual ±3% rule: the diameter differs by +0.58%.
What's the difference between 275/35R19 and 285/30R20?
285/30R20 is 0.15" taller and 10 mm wider; the sidewall is -0.42". At an indicated 60 mph you'd actually be doing 60.3 mph.
Will 285/30R20 fit on 275/35R19 wheels?
No — 275/35R19 needs a 19" wheel and 285/30R20 a 20" wheel. This is a plus/minus-size swap that changes wheels too.