275/65R18 vs 275/70R18
275/70R18 is 1.08 inches taller than 275/65R18 and the same width.
+3.4% height. Outside the usual 3% rule: the speedometer and ride height change noticeably.
| Measurement | 275/65R18 | 275/70R18 | Difference |
|---|---|---|---|
| Overall height | 32.1 in | 33.2 in | +1.08 in (+3.4%) |
| Section width | 10.8 in | 10.8 in | ±0.00 in (±0 mm) |
| Sidewall height | 7.0 in | 7.6 in | +0.54 in |
| Circumference | 100.8 in | 104.2 in | +3.4 in |
| Revolutions per mile | 629 | 608 | −21 |
| Ride height | +0.54 in |
Speedometer
With 275/70R18 fitted, a speedometer set up for 275/65R18 shows the first number when you are really doing the second.
- 3031.0 mph
- 4546.5 mph
- 6062.0 mph
- 7577.5 mph
The two sizes
275/65R18 is 32.1 inches tall with a 7.0-inch sidewall. 275/70R18 is 33.2 inches tall with a 7.6-inch sidewall. A taller sidewall rides softer and gives more ground clearance; a shorter one turns in more sharply. Try other pairs in the tire size calculator.
More comparisons
Questions
Which is bigger, 275/65R18 or 275/70R18?
275/70R18 is taller: 33.2 inches against 32.1. They are the same width.
Can I replace 275/65R18 with 275/70R18?
It is 3.4% taller, outside the usual 3% rule, so expect a noticeable speedometer change and check for rubbing at full lock and full suspension travel.
How much does the speedometer change?
With 275/70R18 on a vehicle set up for 275/65R18, the speedometer shows 60 mph at a true 62.0 mph, and 70 at 72.4.