265/30R20 vs 315/30R20
315/30R20 is outside the ±3% rule as a replacement for 265/30R20: the diameter differs by +4.50%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.
Speedometer and odometer
With 315/30R20 on a car calibrated for 265/30R20, the speedometer reads 57.4 mph when you're really doing 60, and the odometer under-counts by 4.5%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 31.3 mph |
| 45 mph | 47.0 mph |
| 60 mph | 62.7 mph |
| 70 mph | 73.1 mph |
| 80 mph | 83.6 mph |
Other sizes close to 265/30R20
- 265/30R20 vs 235/40R19+0.54%
- 265/30R20 vs 255/35R19-0.88%
- 265/30R20 vs 245/35R20+1.87%
- 265/30R20 vs 255/35R20+2.92%
- 265/30R20 vs 225/40R19-0.66%
- 265/30R20 vs 265/35R19+0.16%
- 265/30R20 vs 285/30R20+1.80%
- 265/30R20 vs 275/30R20+0.90%
- 265/30R20 vs 265/35R20+3.97%
- 265/30R20 vs 235/35R20+0.82%
- 265/30R20 vs 295/30R20+2.70%
- 265/30R20 vs 305/30R20+3.60%
Questions
Can I replace 265/30R20 with 315/30R20?
315/30R20 is outside the ±3% rule as a replacement for 265/30R20: the diameter differs by +4.50%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.
What's the difference between 265/30R20 and 315/30R20?
315/30R20 is 1.18" taller and 50 mm wider; the sidewall is +0.59". At an indicated 60 mph you'd actually be doing 62.7 mph.
Will 315/30R20 fit on 265/30R20 wheels?
Both use a 20" rim, so the wheel diameter matches; check the wheel's width range for a 315 mm tire and the fender clearance.