295/40R18 vs 275/45R18
275/45R18 is a safe swap for 295/40R18 by the usual ±3% rule: the diameter differs by +1.66%.
Speedometer and odometer
With 275/45R18 on a car calibrated for 295/40R18, the speedometer reads 59.0 mph when you're really doing 60, and the odometer under-counts by 1.7%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 30.5 mph |
| 45 mph | 45.7 mph |
| 60 mph | 61.0 mph |
| 70 mph | 71.2 mph |
| 80 mph | 81.3 mph |
Other sizes close to 295/40R18
- 295/40R18 vs 225/45R18-4.83%
- 295/40R18 vs 245/45R18-2.24%
- 295/40R18 vs 235/50R18-0.14%
- 295/40R18 vs 235/55R18+3.25%
- 295/40R18 vs 235/45R18-3.53%
- 295/40R18 vs 235/55R17-0.42%
- 295/40R18 vs 225/60R18+4.90%
- 295/40R18 vs 225/50R18-1.59%
- 295/40R18 vs 255/40R19-0.95%
- 295/40R18 vs 225/55R18+1.66%
- 295/40R18 vs 255/40R18-4.62%
- 295/40R18 vs 215/60R17-0.49%
Questions
Can I replace 295/40R18 with 275/45R18?
275/45R18 is a safe swap for 295/40R18 by the usual ±3% rule: the diameter differs by +1.66%.
What's the difference between 295/40R18 and 275/45R18?
275/45R18 is 0.45" taller and 20 mm narrower; the sidewall is +0.23". At an indicated 60 mph you'd actually be doing 61.0 mph.
Will 275/45R18 fit on 295/40R18 wheels?
Both use a 18" rim, so the wheel diameter matches; check the wheel's width range for a 275 mm tire and the fender clearance.