305/65R18 vs 295/70R18
295/70R18 is a safe swap for 305/65R18 by the usual ±3% rule: the diameter differs by +1.93%.
Speedometer and odometer
With 295/70R18 on a car calibrated for 305/65R18, the speedometer reads 58.9 mph when you're really doing 60, and the odometer under-counts by 1.9%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 30.6 mph |
| 45 mph | 45.9 mph |
| 60 mph | 61.2 mph |
| 70 mph | 71.4 mph |
| 80 mph | 81.5 mph |
Other sizes close to 305/65R18
- 305/65R18 vs 275/65R18-4.57%
- 305/65R18 vs 275/70R18-1.35%
- 305/65R18 vs 265/70R18-2.99%
- 305/65R18 vs 255/70R18-4.63%
- 305/65R18 vs 35x12.50R18+4.13%
- 305/65R18 vs 285/65R18-3.05%
- 305/65R18 vs 33x12.50R18-1.82%
- 305/65R18 vs 285/75R17+0.66%
- 305/65R18 vs 285/75R18+3.63%
- 305/65R18 vs 325/65R18+3.05%
- 305/65R18 vs 305/70R18+3.57%
- 305/65R18 vs 285/70R18+0.29%
Questions
Can I replace 305/65R18 with 295/70R18?
295/70R18 is a safe swap for 305/65R18 by the usual ±3% rule: the diameter differs by +1.93%.
What's the difference between 305/65R18 and 295/70R18?
295/70R18 is 0.65" taller and 10 mm narrower; the sidewall is +0.32". At an indicated 60 mph you'd actually be doing 61.2 mph.
Will 295/70R18 fit on 305/65R18 wheels?
Both use a 18" rim, so the wheel diameter matches; check the wheel's width range for a 295 mm tire and the fender clearance.