295/30R18 vs 315/30R18
315/30R18 is a safe swap for 295/30R18 by the usual ±3% rule: the diameter differs by +1.89%.
Speedometer and odometer
With 315/30R18 on a car calibrated for 295/30R18, 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 | 61.1 mph |
| 70 mph | 71.3 mph |
| 80 mph | 81.5 mph |
Other sizes close to 295/30R18
- 295/30R18 vs 225/45R17+0.02%
- 295/30R18 vs 245/40R18+3.00%
- 295/30R18 vs 225/45R18+4.02%
- 295/30R18 vs 225/40R18+0.47%
- 295/30R18 vs 205/50R17+0.41%
- 295/30R18 vs 235/40R18+1.73%
- 295/30R18 vs 255/35R18+0.24%
- 295/30R18 vs 255/40R18+4.26%
- 295/30R18 vs 275/35R18+2.44%
- 295/30R18 vs 265/35R18+1.34%
- 295/30R18 vs 255/40R17+0.25%
- 295/30R18 vs 215/45R18+2.60%
Questions
Can I replace 295/30R18 with 315/30R18?
315/30R18 is a safe swap for 295/30R18 by the usual ±3% rule: the diameter differs by +1.89%.
What's the difference between 295/30R18 and 315/30R18?
315/30R18 is 0.47" taller and 20 mm wider; the sidewall is +0.24". At an indicated 60 mph you'd actually be doing 61.1 mph.
Will 315/30R18 fit on 295/30R18 wheels?
Both use a 18" rim, so the wheel diameter matches; check the wheel's width range for a 315 mm tire and the fender clearance.