255/35R18 vs 265/35R18 Side-by-side tire size comparison with specs and compatibility
This tire swap is within the safe 3% diameter threshold. It should not cause issues with speedometer accuracy, ABS, or traction control systems.
Full Specifications Comparison
| Specification | 255/35R18 | 265/35R18 | Difference |
|---|---|---|---|
| Overall Diameter | 635.7 mm (25") | 642.7 mm (25.3") | +7 mm |
| Section Width | 255 mm (10") | 265 mm (10.4") | +10 mm |
| Sidewall Height | 89.3 mm | 92.8 mm | +3.5 mm |
| Circumference | 1997.1 mm | 2019.1 mm | +22 mm |
| Revolutions/Mile | 806 | 797 | -9 |
| Aspect Ratio | 35% | 35% | 0% |
| Rim Diameter | 18" | 18" | 0" |
Key Impact Summary
Speedometer Correction Table
When switching from 255/35R18 to 265/35R18, your speedometer will under-read. Here is the correction at common speeds:
| Speedometer Shows | Actual Speed (mph) | Difference |
|---|---|---|
| 30 mph | 30.3 mph | +0.3 mph |
| 40 mph | 40.4 mph | +0.4 mph |
| 50 mph | 50.6 mph | +0.6 mph |
| 60 mph | 60.7 mph | +0.7 mph |
| 70 mph | 70.8 mph | +0.8 mph |
| 80 mph | 80.9 mph | +0.9 mph |
| 90 mph | 91 mph | +1 mph |
| 100 mph | 101.1 mph | +1.1 mph |
| 110 mph | 111.2 mph | +1.2 mph |
| 120 mph | 121.3 mph | +1.3 mph |
What This Swap Means
Wider tires (265/35R18): The 10mm wider contact patch provides better grip in dry conditions and improved cornering stability. However, wider tires increase rolling resistance slightly, which may affect fuel economy by 1-2%. They are also more susceptible to hydroplaning in wet conditions.
Taller sidewall: The 3.5mm increase in sidewall height provides a more comfortable ride by absorbing more road imperfections. Taller sidewalls also offer better protection against pothole damage to wheels. The trade-off is slightly less responsive steering feel.
Ground clearance: Increases by 3.5mm, providing slightly better approach angles for off-road driving and speed bump clearance.