295/40R20 vs 265/40R21
265/40R21 is a safe swap for 295/40R20 by the usual ±3% rule: the diameter differs by +0.19%.
Speedometer and odometer
With 265/40R21 on a car calibrated for 295/40R20, the speedometer reads 59.9 mph when you're really doing 60, and the odometer under-counts by 0.2%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 30.1 mph |
| 45 mph | 45.1 mph |
| 60 mph | 60.1 mph |
| 70 mph | 70.1 mph |
| 80 mph | 80.2 mph |
Other sizes close to 295/40R20
- 295/40R20 vs 235/55R19-0.39%
- 295/40R20 vs 245/45R20-2.08%
- 295/40R20 vs 255/45R20-0.87%
- 295/40R20 vs 255/50R19-0.86%
- 295/40R20 vs 275/40R20-2.15%
- 295/40R20 vs 255/50R20+2.55%
- 295/40R20 vs 265/50R20+3.90%
- 295/40R20 vs 245/50R20+1.21%
- 295/40R20 vs 275/45R20+1.55%
- 295/40R20 vs 235/55R20+3.02%
- 295/40R20 vs 255/40R20-4.30%
- 295/40R20 vs 265/45R20+0.34%
Questions
Can I replace 295/40R20 with 265/40R21?
265/40R21 is a safe swap for 295/40R20 by the usual ±3% rule: the diameter differs by +0.19%.
What's the difference between 295/40R20 and 265/40R21?
265/40R21 is 0.06" taller and 30 mm narrower; the sidewall is -0.47". At an indicated 60 mph you'd actually be doing 60.1 mph.
Will 265/40R21 fit on 295/40R20 wheels?
No — 295/40R20 needs a 20" wheel and 265/40R21 a 21" wheel. This is a plus/minus-size swap that changes wheels too.