265/65R18 vs 285/65R18: full comparison
| Measurement | 265/65R18 | 285/65R18 | Difference |
|---|---|---|---|
| Diameter | 31.56 in | 32.59 in | +1.02 in+3.2% |
| Section width | 10.43 in | 11.22 in | +0.79 in+7.5% |
| Sidewall height | 6.78 in | 7.29 in | +0.51 in+7.5% |
| Circumference | 99.16 in | 102.37 in | +3.22 in+3.2% |
| Revs per mile | 639 | 619 | −20−3.1% |
Speedometer: indicated vs actual speed
With 285/65R18 fitted where 265/65R18 was the stock/calibrated size:
| Speedometer shows | Actual speed | Difference |
|---|---|---|
| 20 mph | 20.6 mph | +0.6 mph |
| 30 mph | 31.0 mph | +1.0 mph |
| 40 mph | 41.3 mph | +1.3 mph |
| 50 mph | 51.6 mph | +1.6 mph |
| 55 mph | 56.8 mph | +1.8 mph |
| 60 mph | 61.9 mph | +1.9 mph |
| 65 mph | 67.1 mph | +2.1 mph |
| 70 mph | 72.3 mph | +2.3 mph |
| 75 mph | 77.4 mph | +2.4 mph |
| 80 mph | 82.6 mph | +2.6 mph |
Recalculate for a gear ratio change too →
Will 285/65R18 fit where 265/65R18 was?
At +3.2%, 285/65R18 is enough larger than 265/65R18 that it commonly needs some accommodation -- trimming plastic liners/fender edges, a spacer, or a leveling kit on trucks/SUVs going bigger. Check clearance at full steering lock and full suspension compression before buying.
Related tire size comparisons
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 285/65R18 than 265/65R18?
285/65R18 is 1.02 in taller in overall diameter (+3.2%) and 0.79 in wider in section width (+7.5%) than 265/65R18.
Will 285/65R18 fit in place of 265/65R18?
At +3.2%, 285/65R18 is enough larger than 265/65R18 that it commonly needs some accommodation -- trimming plastic liners/fender edges, a spacer, or a leveling kit on trucks/SUVs going bigger. Check clearance at full steering lock and full suspension compression before buying.
Does swapping to 285/65R18 affect my speedometer?
With 285/65R18 fitted where 265/65R18 was calibrated, an indicated 60 mph is really about 61.9 mph. Beyond the ±3% guideline, plan to recalibrate the speedometer/odometer (with a programmer or at the dealer) for an accurate reading.
Does 285/65R18 change the ride height?
Yes -- half the diameter difference shows up at the axle, so 285/65R18 changes ride height by about 0.51 in higher compared with 265/65R18.
Do 265/65R18 and 285/65R18 use the same wheel (rim) diameter?
Yes -- both fit a 18 inch wheel, so only the tire itself changes, not the wheel.