265/70R17 vs 285/70R17
285/70R17 is 1.1 inches taller and 0.8 inches wider. When your speedometer says 60 mph, you'd really be doing 62.1.
I have 265/70R17
I'm looking at 285/70R17
Possible, with caveats
1.1 in taller. At 60 mph on the speedometer you'd really be doing 62.1.
- More than 3% taller. Expect a noticeable speedometer error, and check that it clears the fenders and suspension when turning. Trucks often need a leveling kit.
- 20 mm wider. Check it clears the suspension inside and the fender outside, and that your wheels are wide enough.
265/70R17 now 285/70R17 newTo scale
At an indicated 60 mph you're really doing 62.1 mph
+1.10″
Height
+0.79″
Width
+0.55″
Sidewall
All measurements
| 265/70R17 | 285/70R17 | Change | |
|---|---|---|---|
| Overall height | 31.61″ | 32.71″ | +1.10″ |
| Section width | 10.43″ | 11.22″ | +0.79″ |
| Sidewall height | 7.30″ | 7.85″ | +0.55″ |
| Wheel size | 17″ | 17″ | same |
| Distance per turn | 99.29″ | 102.76″ | +3.46″ |
| Turns per mile | 638 | 617 | −22 |
Speedometer after switching
Your speedometer is calibrated for 265/70R17. On 285/70R17:
| Speedometer says | You're really doing |
|---|---|
| 25 mph | 25.9 mph |
| 35 mph | 36.2 mph |
| 45 mph | 46.6 mph |
| 55 mph | 56.9 mph |
| 65 mph | 67.3 mph |
| 75 mph | 77.6 mph |
What changes on the vehicle
- Ride height goes up about 0.55″ (half the height difference).
- The tire turns 22 fewer times per mile, so your odometer will read low by about 3.5%.
- The sidewall is 0.55″ taller, on the same wheels.