275/35R21 vs 285/30R22
285/30R22 is a safe swap for 275/35R21 by the usual ±3% rule: the diameter differs by +0.54%.
Speedometer and odometer
With 285/30R22 on a car calibrated for 275/35R21, the speedometer reads 59.7 mph when you're really doing 60, and the odometer under-counts by 0.5%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 30.2 mph |
| 45 mph | 45.2 mph |
| 60 mph | 60.3 mph |
| 70 mph | 70.4 mph |
| 80 mph | 80.4 mph |
Other sizes close to 275/35R21
- 275/35R21 vs 245/45R20+0.36%
- 275/35R21 vs 275/40R20+0.29%
- 275/35R21 vs 265/40R21+2.69%
- 275/35R21 vs 315/35R20+0.36%
- 275/35R21 vs 295/35R21+1.93%
- 275/35R21 vs 255/40R21+1.58%
- 275/35R21 vs 265/35R21-0.96%
- 275/35R21 vs 245/35R21-2.89%
- 275/35R21 vs 305/35R20-0.61%
- 275/35R21 vs 285/40R21+4.89%
- 275/35R21 vs 325/30R21+0.34%
- 275/35R21 vs 275/40R21+3.79%
Questions
Can I replace 275/35R21 with 285/30R22?
285/30R22 is a safe swap for 275/35R21 by the usual ±3% rule: the diameter differs by +0.54%.
What's the difference between 275/35R21 and 285/30R22?
285/30R22 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 285/30R22 fit on 275/35R21 wheels?
No — 275/35R21 needs a 21" wheel and 285/30R22 a 22" wheel. This is a plus/minus-size swap that changes wheels too.