The new tire changes overall diameter by -9.3%. With a speedometer calibrated to the original tire, that same percentage is how far the speedometer and odometer read off — a taller tire means your true speed is higher than indicated and the odometer under-counts distance.
| Speedo shows | True speed | Speedo shows | True speed |
|---|---|---|---|
| 40 km/h | 36.3 km/h | 25 mph | 23 mph |
| 60 km/h | 54.4 km/h | 37 mph | 34 mph |
| 80 km/h | 72.6 km/h | 50 mph | 45 mph |
| 100 km/h | 90.7 km/h | 62 mph | 56 mph |
| 120 km/h | 108.8 km/h | 75 mph | 68 mph |
Commonly compared with 235/65R17
- 235/65R17 vs 255/55R18 · 255/55R18 specs
- 235/65R17 vs 235/70R16 · 235/70R16 specs
- 235/65R17 vs 235/60R18 · 235/60R18 specs
- 235/65R17 vs 245/70R16 · 245/70R16 specs
- 235/65R17 vs 225/65R17 · 225/65R17 specs
- 235/65R17 vs 245/65R17 · 245/65R17 specs
- 235/65R17 vs 245/60R18 · 245/60R18 specs
- 235/65R17 vs 225/70R16 · 225/70R16 specs
FAQ
What is the overall diameter of a 235/65R17 tire?
A 235/65R17 tire has an overall diameter of about 29.03 inches (737 mm) and a section width of 235 mm.
What sizes can replace a 235/65R17 tire?
Sizes within about ±3% of 235/65R17's 29.0-inch diameter are the closest matches, such as 255/55R18, 235/70R16, 235/60R18. Use the calculator above to check the exact speedometer effect of any substitute.
Fitment & trouble codes
Changing tire size by more than about 3% shifts the speedometer, odometer and, on some vehicles, ABS/traction calibration — which can set wheel-speed-sensor or vehicle-speed codes. See C1234 (wheel speed sensor) and C0050 (rear wheel speed) if a warning light appears after a size change.