325/30R19 vs 265/40R19
265/40R19 is a safe swap for 325/30R19 by the usual ±3% rule: the diameter differs by +2.51%.
Speedometer and odometer
With 265/40R19 on a car calibrated for 325/30R19, the speedometer reads 58.5 mph when you're really doing 60, and the odometer under-counts by 2.5%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 30.8 mph |
| 45 mph | 46.1 mph |
| 60 mph | 61.5 mph |
| 70 mph | 71.8 mph |
| 80 mph | 82.0 mph |
Other sizes close to 325/30R19
- 325/30R19 vs 245/45R18+0.01%
- 325/30R19 vs 245/45R19+3.76%
- 325/30R19 vs 245/40R19+0.15%
- 325/30R19 vs 225/50R18+0.68%
- 325/30R19 vs 235/40R19-1.03%
- 325/30R19 vs 255/40R19+1.33%
- 325/30R19 vs 255/35R19-2.44%
- 325/30R19 vs 275/35R19-0.37%
- 325/30R19 vs 275/40R19+3.69%
- 325/30R19 vs 245/35R20+0.28%
- 325/30R19 vs 245/35R19-3.47%
- 325/30R19 vs 225/40R19-2.21%
Questions
Can I replace 325/30R19 with 265/40R19?
265/40R19 is a safe swap for 325/30R19 by the usual ±3% rule: the diameter differs by +2.51%.
What's the difference between 325/30R19 and 265/40R19?
265/40R19 is 0.67" taller and 60 mm narrower; the sidewall is +0.33". At an indicated 60 mph you'd actually be doing 61.5 mph.
Will 265/40R19 fit on 325/30R19 wheels?
Both use a 19" rim, so the wheel diameter matches; check the wheel's width range for a 265 mm tire and the fender clearance.