175/70R14 vs 175/65R15
175/65R15 is taller than 175/70R14 by 1.32% — a diameter difference of 0.31″.
What changes between 175/70R14 and 175/65R15
Switching from 175/70R14 to 175/65R15 changes overall diameter by +1.32%, a taller tire by 0.31 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 0.00″ (175mm → 175mm), which affects contact patch and fender-well clearance. Sidewall height shifts by -0.34″: a shorter sidewall sharpens steering response at the cost of ride comfort and rim protection. Revs per mile moves by -11, which translates directly to speedometer error — at an indicated 65 mph, actual speed becomes 65.8 mph. The swap also changes rim diameter from 14″ to 15″, meaning new wheels are required. Wheel cost typically dominates the total upsize budget.
| Spec | 175/70R14 | 175/65R15 |
|---|---|---|
| Overall diameter | 23.65″ | 23.96″ |
| Section width | 6.89″ (175 mm) | 6.89″ (175 mm) |
| Sidewall height | 4.82″ (70%) | 4.48″ (65%) |
| Rim diameter | 14″ | 15″ |
| Circumference | 74.29″ | 75.26″ |
| Revs per mile | 853 | 842 |
Interactive comparison
275/65R18 or "33" for inch aliases175/70R14
- Diameter
- 23.65″ / 600.6mm
- Section Width
- 6.89″
- Sidewall
- 4.82″ / 122.5mm
- Circumference
- 74.29″
- Revs/Mile
- 853
175/65R15
- Diameter
- 23.96″ / 608.5mm
- Section Width
- 6.89″
- Sidewall
- 4.48″ / 113.75mm
- Circumference
- 75.26″
- Revs/Mile
- 842
Speedometer & Diameter Impact
Different rim — new wheels requiredAt an indicated 60 mph, your actual speed is 60.79 mph (97.83 km/h). Your speedometer reads 1.32% low versus actual speed.