275/70R17 vs 305/70R17
305/70R17 is outside the ±3% rule as a replacement for 275/70R17: the diameter differs by +5.14%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.
Speedometer and odometer
With 305/70R17 on a car calibrated for 275/70R17, the speedometer reads 57.1 mph when you're really doing 60, and the odometer under-counts by 5.1%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 31.5 mph |
| 45 mph | 47.3 mph |
| 60 mph | 63.1 mph |
| 70 mph | 73.6 mph |
| 80 mph | 84.1 mph |
Other sizes close to 275/70R17
- 275/70R17 vs 265/70R17-1.71%
- 275/70R17 vs 275/65R18-0.26%
- 275/70R17 vs 285/70R17+1.71%
- 275/70R17 vs 245/75R17-2.14%
- 275/70R17 vs 265/65R17-4.96%
- 275/70R17 vs 235/80R17-1.10%
- 275/70R17 vs 255/70R18-0.32%
- 275/70R17 vs 255/70R17-3.43%
- 275/70R17 vs 255/75R17-0.31%
- 275/70R17 vs 295/70R17+3.43%
- 275/70R17 vs 235/75R17-3.98%
- 275/70R17 vs 33x12.50R17+2.62%
Questions
Can I replace 275/70R17 with 305/70R17?
305/70R17 is outside the ±3% rule as a replacement for 275/70R17: the diameter differs by +5.14%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.
What's the difference between 275/70R17 and 305/70R17?
305/70R17 is 1.65" taller and 30 mm wider; the sidewall is +0.83". At an indicated 60 mph you'd actually be doing 63.1 mph.
Will 305/70R17 fit on 275/70R17 wheels?
Both use a 17" rim, so the wheel diameter matches; check the wheel's width range for a 305 mm tire and the fender clearance.