255/70R18 vs 265/70R18: Tire Size Comparison
265/70R18 is 0.55 inches taller than 255/70R18 (32.61″ vs 32.06″, +1.72%) and 0.39 inches wider. The difference is within the common ±3% guideline. At an indicated 60 mph you would be doing 61 mph.
| 255/70R18 | 265/70R18 | Difference | |
|---|---|---|---|
| Overall diameter | 32.06 in | 32.61 in | +0.55 |
| Section width | 10.04 in | 10.43 in | +0.39 |
| Sidewall height | 7.03 in | 7.3 in | +0.28 |
| Circumference | 100.7 in | 102.4 in | +1.73 |
| Revolutions per mile | 629 | 619 | −11 |
255/70R18 vs 265/70R18 dimensions
| 255/70R18 | 265/70R18 | Difference | |
|---|---|---|---|
| Overall diameter | 32.06 in (814 mm) | 32.61 in (828 mm) | +0.55 in (+1.72%) |
| Section width | 10.04 in | 10.43 in | +0.39 in |
| Sidewall height | 7.03 in | 7.3 in | +0.28 in |
| Wheel diameter | 18 in | 18 in | same wheel |
| Circumference | 100.7 in | 102.4 in | +1.73 in |
| Revolutions per mile | 629 | 619 | -11 |
Nominal dimensions calculated from the size code. Real tires vary slightly by brand, tread depth and inflation.
Speedometer difference with 265/70R18
| Speedometer shows | Actual speed on 265/70R18 | Difference |
|---|---|---|
| 30 mph | 30.5 mph | +0.5 mph |
| 45 mph | 45.8 mph | +0.8 mph |
| 60 mph | 61 mph | +1 mph |
| 70 mph | 71.2 mph | +1.2 mph |
| 80 mph | 81.4 mph | +1.4 mph |
Assumes your speedometer is accurate on 255/70R18. Because 265/70R18 is taller, you travel slightly faster than indicated and the odometer under-counts: 10,000 miles on the odometer is about 10,172 real miles.
What changes if you switch
- Ride height: up about 0.28 in (half the diameter change).
- Wheels: both fit a 18-inch wheel; check the tire's approved rim width range.
- Sidewall: a taller sidewall usually rides softer and resists pothole damage, with a little less steering sharpness.
- Effective gearing: slightly taller, so marginally lower engine rpm at speed and slightly slower acceleration.
- Match the original load index and speed rating or higher, and check for rubbing at full steering lock and full suspension compression.
Related tire size comparisons
Frequently asked questions
Can I use 265/70R18 instead of 255/70R18?
265/70R18 is +1.72% in overall diameter compared with 255/70R18 (32.61″ vs 32.06″). That is inside the common ±3% guideline, so it is often used as an alternative. Check your vehicle placard, load index, speed rating and clearance before switching.
How much taller is 265/70R18 than 255/70R18?
265/70R18 is 0.55 inches taller overall, which raises ride height by about 0.28 inches. Sidewall height changes from 7.03″ to 7.3″.
How much wider is 265/70R18 than 255/70R18?
Section width goes from 10.04″ (255 mm) to 10.43″ (265 mm), a difference of +0.39 in. Actual width also depends on the rim width it is mounted on.
How does 265/70R18 affect my speedometer?
With 265/70R18 fitted in place of 255/70R18, when the speedometer shows 60 mph you are actually going about 61 mph. The odometer will record 10,000 miles when you have driven about 10,172.