285/65R18 vs 285/70R17
285/70R17 is a safe swap for 285/65R18 by the usual ±3% rule: the diameter differs by +0.37%.
Speedometer and odometer
With 285/70R17 on a car calibrated for 285/65R18, the speedometer reads 59.8 mph when you're really doing 60, and the odometer under-counts by 0.4%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 30.1 mph |
| 45 mph | 45.2 mph |
| 60 mph | 60.2 mph |
| 70 mph | 70.3 mph |
| 80 mph | 80.3 mph |
Other sizes close to 285/65R18
- 285/65R18 vs 275/65R18-1.57%
- 285/65R18 vs 275/70R18+1.75%
- 285/65R18 vs 265/65R18-3.14%
- 285/65R18 vs 265/70R18+0.06%
- 285/65R18 vs 255/70R18-1.63%
- 285/65R18 vs 255/65R18-4.71%
- 285/65R18 vs 33x12.50R18+1.27%
- 285/65R18 vs 285/60R18-3.44%
- 285/65R18 vs 305/65R18+3.14%
- 285/65R18 vs 275/60R18-4.89%
- 285/65R18 vs 305/60R18-0.54%
- 285/65R18 vs 285/70R18+3.44%
Questions
Can I replace 285/65R18 with 285/70R17?
285/70R17 is a safe swap for 285/65R18 by the usual ±3% rule: the diameter differs by +0.37%.
What's the difference between 285/65R18 and 285/70R17?
285/70R17 is 0.12" taller and 0 mm wider; the sidewall is +0.56". At an indicated 60 mph you'd actually be doing 60.2 mph.
Will 285/70R17 fit on 285/65R18 wheels?
No — 285/65R18 needs a 18" wheel and 285/70R17 a 17" wheel. This is a plus/minus-size swap that changes wheels too.