255/70R17 vs 265/70R17
265/70R17 is taller than 255/70R17 by 1.77% — a diameter difference of 0.55″.
What changes between 255/70R17 and 265/70R17
Switching from 255/70R17 to 265/70R17 changes overall diameter by +1.77%, a taller tire by 0.55 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″ (255mm → 265mm), 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 -11, which translates directly to speedometer error — at an indicated 65 mph, actual speed becomes 66.2 mph. Both sizes share the same 17″ rim, so no wheel change is required — this is a pure tire-only swap.
| Spec | 255/70R17 | 265/70R17 |
|---|---|---|
| Overall diameter | 31.06″ | 31.61″ |
| Section width | 10.04″ (255 mm) | 10.43″ (265 mm) |
| Sidewall height | 7.03″ (70%) | 7.3″ (70%) |
| Rim diameter | 17″ | 17″ |
| Circumference | 97.56″ | 99.29″ |
| Revs per mile | 649 | 638 |
Interactive comparison
275/65R18 or "33" for inch aliases255/70R17
- Diameter
- 31.06″ / 788.8mm
- Section Width
- 10.04″
- Sidewall
- 7.03″ / 178.5mm
- Circumference
- 97.56″
- Revs/Mile
- 649
265/70R17
- Diameter
- 31.61″ / 802.8mm
- Section Width
- 10.43″
- Sidewall
- 7.3″ / 185.5mm
- Circumference
- 99.29″
- Revs/Mile
- 638
Speedometer & Diameter Impact
At an indicated 60 mph, your actual speed is 61.06 mph (98.27 km/h). Your speedometer reads 1.77% low versus actual speed.