265/70R17 vs 255/75R17
255/75R17 is taller than 265/70R17 by 1.43% — a diameter difference of 0.45″.
What changes between 265/70R17 and 255/75R17
Switching from 265/70R17 to 255/75R17 changes overall diameter by +1.43%, a taller tire by 0.45 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 +0.23″: a taller sidewall softens ride quality and adds off-road bump protection, with some loss of steering crispness. Revs per mile moves by -9, which translates directly to speedometer error — at an indicated 65 mph, actual speed becomes 65.9 mph. Both sizes share the same 17″ rim, so no wheel change is required — this is a pure tire-only swap.
| Spec | 265/70R17 | 255/75R17 |
|---|---|---|
| Overall diameter | 31.61″ | 32.06″ |
| Section width | 10.43″ (265 mm) | 10.04″ (255 mm) |
| Sidewall height | 7.3″ (70%) | 7.53″ (75%) |
| Rim diameter | 17″ | 17″ |
| Circumference | 99.29″ | 100.72″ |
| Revs per mile | 638 | 629 |
Interactive comparison
275/65R18 or "33" for inch aliases265/70R17
- Diameter
- 31.61″ / 802.8mm
- Section Width
- 10.43″
- Sidewall
- 7.3″ / 185.5mm
- Circumference
- 99.29″
- Revs/Mile
- 638
255/75R17
- Diameter
- 32.06″ / 814.3mm
- Section Width
- 10.04″
- Sidewall
- 7.53″ / 191.25mm
- Circumference
- 100.72″
- Revs/Mile
- 629
Speedometer & Diameter Impact
At an indicated 60 mph, your actual speed is 60.86 mph (97.94 km/h). Your speedometer reads 1.43% low versus actual speed.