265/30R20 vs 255/35R20
255/35R20 is a safe swap for 265/30R20 by the usual ±3% rule: the diameter differs by +2.92%.
Speedometer and odometer
With 255/35R20 on a car calibrated for 265/30R20, the speedometer reads 58.3 mph when you're really doing 60, and the odometer under-counts by 2.9%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 30.9 mph |
| 45 mph | 46.3 mph |
| 60 mph | 61.8 mph |
| 70 mph | 72.0 mph |
| 80 mph | 82.3 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 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%
- 265/30R20 vs 305/30R19-0.21%
Questions
Can I replace 265/30R20 with 255/35R20?
255/35R20 is a safe swap for 265/30R20 by the usual ±3% rule: the diameter differs by +2.92%.
What's the difference between 265/30R20 and 255/35R20?
255/35R20 is 0.77" taller and 10 mm narrower; the sidewall is +0.38". At an indicated 60 mph you'd actually be doing 61.8 mph.
Will 255/35R20 fit on 265/30R20 wheels?
Both use a 20" rim, so the wheel diameter matches; check the wheel's width range for a 255 mm tire and the fender clearance.