245/75R17 vs 275/70R17
275/70R17 is taller than 245/75R17 by 2.19% — a diameter difference of 0.69″.
What changes between 245/75R17 and 275/70R17
Switching from 245/75R17 to 275/70R17 changes overall diameter by +2.19%, a taller tire by 0.69 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 +1.18″ (245mm → 275mm), which affects contact patch and fender-well clearance. Sidewall height shifts by +0.35″: a taller sidewall softens ride quality and adds off-road bump protection, with some loss of steering crispness. Revs per mile moves by -14, which translates directly to speedometer error — at an indicated 65 mph, actual speed becomes 66.4 mph. Both sizes share the same 17″ rim, so no wheel change is required — this is a pure tire-only swap.
| Spec | 245/75R17 | 275/70R17 |
|---|---|---|
| Overall diameter | 31.47″ | 32.16″ |
| Section width | 9.65″ (245 mm) | 10.83″ (275 mm) |
| Sidewall height | 7.23″ (75%) | 7.58″ (70%) |
| Rim diameter | 17″ | 17″ |
| Circumference | 98.86″ | 101.03″ |
| Revs per mile | 641 | 627 |
Interactive comparison
275/65R18 or "33" for inch aliases245/75R17
- Diameter
- 31.47″ / 799.3mm
- Section Width
- 9.65″
- Sidewall
- 7.23″ / 183.75mm
- Circumference
- 98.86″
- Revs/Mile
- 641
275/70R17
- Diameter
- 32.16″ / 816.8mm
- Section Width
- 10.83″
- Sidewall
- 7.58″ / 192.5mm
- Circumference
- 101.03″
- Revs/Mile
- 627
Speedometer & Diameter Impact
Wider tire — verify wheel widthAt an indicated 60 mph, your actual speed is 61.31 mph (98.67 km/h). Your speedometer reads 2.19% low versus actual speed.