285/45R21 vs 295/40R22
295/40R22 is a safe swap for 285/45R21 by the usual ±3% rule: the diameter differs by +0.62%.
Speedometer and odometer
With 295/40R22 on a car calibrated for 285/45R21, the speedometer reads 59.6 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 | 60.4 mph |
| 70 mph | 70.4 mph |
| 80 mph | 80.5 mph |
Other sizes close to 285/45R21
- 285/45R21 vs 255/55R20-0.18%
- 285/45R21 vs 275/50R20-0.87%
- 285/45R21 vs 275/45R21-1.14%
- 285/45R21 vs 285/40R22-0.39%
- 285/45R21 vs 295/40R21-2.60%
- 285/45R21 vs 285/50R20+0.39%
- 285/45R21 vs 265/45R21-2.28%
- 285/45R21 vs 285/40R21-3.61%
- 285/45R21 vs 275/40R21-4.62%
- 285/45R21 vs 315/35R21-4.56%
- 285/45R21 vs 315/40R21-0.57%
- 285/45R21 vs 325/35R22-0.46%
Questions
Can I replace 285/45R21 with 295/40R22?
295/40R22 is a safe swap for 285/45R21 by the usual ±3% rule: the diameter differs by +0.62%.
What's the difference between 285/45R21 and 295/40R22?
295/40R22 is 0.19" taller and 10 mm wider; the sidewall is -0.40". At an indicated 60 mph you'd actually be doing 60.4 mph.
Will 295/40R22 fit on 285/45R21 wheels?
No — 285/45R21 needs a 21" wheel and 295/40R22 a 22" wheel. This is a plus/minus-size swap that changes wheels too.