265/70R17 vs 315/70R17: full comparison
| Measurement | 265/70R17 | 315/70R17 | Difference |
|---|---|---|---|
| Diameter | 31.61 in | 34.36 in | +2.76 in+8.7% |
| Section width | 10.43 in | 12.40 in | +1.97 in+18.9% |
| Sidewall height | 7.30 in | 8.68 in | +1.38 in+18.9% |
| Circumference | 99.29 in | 107.95 in | +8.66 in+8.7% |
| Revs per mile | 638 | 587 | −51−8.0% |
Speedometer: indicated vs actual speed
With 315/70R17 fitted where 265/70R17 was the stock/calibrated size:
| Speedometer shows | Actual speed | Difference |
|---|---|---|
| 20 mph | 21.7 mph | +1.7 mph |
| 30 mph | 32.6 mph | +2.6 mph |
| 40 mph | 43.5 mph | +3.5 mph |
| 50 mph | 54.4 mph | +4.4 mph |
| 55 mph | 59.8 mph | +4.8 mph |
| 60 mph | 65.2 mph | +5.2 mph |
| 65 mph | 70.7 mph | +5.7 mph |
| 70 mph | 76.1 mph | +6.1 mph |
| 75 mph | 81.5 mph | +6.5 mph |
| 80 mph | 87.0 mph | +7.0 mph |
Recalculate for a gear ratio change too →
Will 315/70R17 fit where 265/70R17 was?
At +8.7%, this is a large change (well outside the ±3% guideline). Going larger by this much typically needs a lift and/or trimming, may need re-gearing (a numerically higher axle ratio) to recover acceleration and towing, and should be checked carefully for clearance and speedometer/ABS recalibration before buying.
Related tire size comparisons
- 265/70R17 vs 285/70R17
- 245/75R17 vs 265/70R17
- 265/65R17 vs 265/70R17
- 245/70R17 vs 265/70R17
- 255/75R17 vs 265/70R17
More tire tools
- Tire size comparison tool: compare any two sizes yourself, including flotation sizes.
- Tire size calculator: full dimensions of one size, plus every equivalent size within 3%.
- Speedometer calculator: true speed after a tire or gear ratio change.
Frequently asked questions
How much bigger is 315/70R17 than 265/70R17?
315/70R17 is 2.76 in taller in overall diameter (+8.7%) and 1.97 in wider in section width (+18.9%) than 265/70R17.
Will 315/70R17 fit in place of 265/70R17?
At +8.7%, this is a large change (well outside the ±3% guideline). Going larger by this much typically needs a lift and/or trimming, may need re-gearing (a numerically higher axle ratio) to recover acceleration and towing, and should be checked carefully for clearance and speedometer/ABS recalibration before buying.
Does swapping to 315/70R17 affect my speedometer?
With 315/70R17 fitted where 265/70R17 was calibrated, an indicated 60 mph is really about 65.2 mph. Beyond the ±3% guideline, plan to recalibrate the speedometer/odometer (with a programmer or at the dealer) for an accurate reading.
Does 315/70R17 change the ride height?
Yes -- half the diameter difference shows up at the axle, so 315/70R17 changes ride height by about 1.38 in higher compared with 265/70R17.
Do 265/70R17 and 315/70R17 use the same wheel (rim) diameter?
Yes -- both fit a 17 inch wheel, so only the tire itself changes, not the wheel.