265/40R22 vs 265/45R21
265/45R21 is a safe swap for 265/40R22 by the usual ±3% rule: the diameter differs by +0.14%.
Speedometer and odometer
With 265/45R21 on a car calibrated for 265/40R22, the speedometer reads 59.9 mph when you're really doing 60, and the odometer under-counts by 0.1%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 30.0 mph |
| 45 mph | 45.1 mph |
| 60 mph | 60.1 mph |
| 70 mph | 70.1 mph |
| 80 mph | 80.1 mph |
Other sizes close to 265/40R22
- 265/40R22 vs 275/40R22+1.04%
- 265/40R22 vs 265/35R22-3.44%
- 265/40R22 vs 285/35R22-1.62%
- 265/40R22 vs 285/40R22+2.08%
- 265/40R22 vs 295/40R21-0.18%
- 265/40R22 vs 275/45R22+4.61%
- 265/40R22 vs 275/35R22-2.53%
- 265/40R22 vs 305/40R22+4.15%
- 265/40R22 vs 295/35R22-0.71%
- 265/40R22 vs 315/35R22+1.10%
- 265/40R22 vs 325/35R22+2.01%
- 265/40R22 vs 295/30R22-4.54%
Questions
Can I replace 265/40R22 with 265/45R21?
265/45R21 is a safe swap for 265/40R22 by the usual ±3% rule: the diameter differs by +0.14%.
What's the difference between 265/40R22 and 265/45R21?
265/45R21 is 0.04" taller and 0 mm wider; the sidewall is +0.52". At an indicated 60 mph you'd actually be doing 60.1 mph.
Will 265/45R21 fit on 265/40R22 wheels?
No — 265/40R22 needs a 22" wheel and 265/45R21 a 21" wheel. This is a plus/minus-size swap that changes wheels too.