265/60R20 vs 255/65R20
255/65R20 is taller than 265/60R20 by 1.63% — a diameter difference of 0.53″.
What changes between 265/60R20 and 255/65R20
Switching from 265/60R20 to 255/65R20 changes overall diameter by +1.63%, a taller tire by 0.53 inches. This lands inside the ±3% fitment safe zone, so most vehicles will accept the swap without rubbing, speedometer recalibration, or ABS/TPMS complications. Section width moves by -0.39″ (265mm → 255mm), which affects contact patch and fender-well clearance. Sidewall height shifts by +0.27″: a taller sidewall softens ride quality and adds off-road bump protection, with some loss of steering crispness. Revs per mile moves by -10, which translates directly to speedometer error — at an indicated 65 mph, actual speed becomes 66.1 mph. Both sizes share the same 20″ rim, so no wheel change is required — this is a pure tire-only swap.
| Spec | 265/60R20 | 255/65R20 |
|---|---|---|
| Overall diameter | 32.52″ | 33.05″ |
| Section width | 10.43″ (265 mm) | 10.04″ (255 mm) |
| Sidewall height | 6.26″ (60%) | 6.53″ (65%) |
| Rim diameter | 20″ | 20″ |
| Circumference | 102.16″ | 103.83″ |
| Revs per mile | 620 | 610 |
Interactive comparison
275/65R18 or "33" for inch aliases265/60R20
- Diameter
- 32.52″ / 826mm
- Section Width
- 10.43″
- Sidewall
- 6.26″ / 159mm
- Circumference
- 102.16″
- Revs/Mile
- 620
255/65R20
- Diameter
- 33.05″ / 839.5mm
- Section Width
- 10.04″
- Sidewall
- 6.53″ / 165.75mm
- Circumference
- 103.83″
- Revs/Mile
- 610
Speedometer & Diameter Impact
At an indicated 60 mph, your actual speed is 60.98 mph (98.14 km/h). Your speedometer reads 1.63% low versus actual speed.