275/70R18 vs 285/65R18
285/65R18 is 0.57 inches shorter than 275/70R18 and 10 mm (0.4 in) wider.
−1.7% height. Inside the usual 3% rule for a swap.
| Measurement | 275/70R18 | 285/65R18 | Difference |
|---|---|---|---|
| Overall height | 33.2 in | 32.6 in | −0.57 in (−1.7%) |
| Section width | 10.8 in | 11.2 in | +0.39 in (+10 mm) |
| Sidewall height | 7.6 in | 7.3 in | −0.29 in |
| Circumference | 104.2 in | 102.4 in | −1.8 in |
| Revolutions per mile | 608 | 619 | +11 |
| Ride height | −0.29 in |
Speedometer
With 285/65R18 fitted, a speedometer set up for 275/70R18 shows the first number when you are really doing the second.
- 3029.5 mph
- 4544.2 mph
- 6059.0 mph
- 7573.7 mph
The two sizes
275/70R18 is 33.2 inches tall with a 7.6-inch sidewall. 285/65R18 is 32.6 inches tall with a 7.3-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, 275/70R18 or 285/65R18?
275/70R18 is taller: 33.2 inches against 32.6. 285/65R18 is wider, at 285 mm.
Can I replace 275/70R18 with 285/65R18?
On height, yes: the difference is 1.7%, inside the usual 3% rule. Check that the extra width clears the suspension and suits your rim width.
How much does the speedometer change?
With 285/65R18 on a vehicle set up for 275/70R18, the speedometer shows 60 mph at a true 59.0 mph, and 70 at 68.8.