Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 325/40-18 | 235/45-18 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 28.24 (717.2) | 26.33 (668.7) | -1.91 (-48.5) -6.8% |
| Width inches (mm) | 12.8 (325) | 9.25 (235) | -3.54 (-90) -27.7% |
| Circum. inches (mm) | 88.71 (2253.15) | 82.71 (2100.78) | -6 (-152.37) -6.8% |
| Sidewall Height inches (mm) | 5.12 (130) | 4.16 (105.75) | -0.95 (-24.25) -18.7% |
| Revolutions per mile (km) | 714.26 (443.82) | 766.07 (476.01) | 51.8 (32.19) 7.3% |
235/45-18 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 18.65 mph (30.01 km/h) |
| 25 mph (40.23 km/h) | 23.31 mph (37.51 km/h) |
| 30 mph (48.28 km/h) | 27.97 mph (45.02 km/h) |
| 35 mph (56.33 km/h) | 32.63 mph (52.52 km/h) |
| 40 mph (64.37 km/h) | 37.3 mph (60.02 km/h) |
| 45 mph (72.42 km/h) | 41.96 mph (67.52 km/h) |
| 50 mph (80.47 km/h) | 46.62 mph (75.03 km/h) |
| 55 mph (88.51 km/h) | 51.28 mph (82.53 km/h) |
| 60 mph (96.56 km/h) | 55.94 mph (90.03 km/h) |
| 65 mph (104.61 km/h) | 60.6 mph (97.53 km/h) |
| 70 mph (112.65 km/h) | 65.27 mph (105.04 km/h) |
| 75 mph (120.7 km/h) | 69.93 mph (112.54 km/h) |
| 80 mph (128.75 km/h) | 74.59 mph (120.04 km/h) |
| 85 mph (136.79 km/h) | 79.25 mph (127.54 km/h) |
| 90 mph (144.84 km/h) | 83.91 mph (135.05 km/h) |
| 95 mph (152.89 km/h) | 88.58 mph (142.55 km/h) |
| 100 mph (160.93 km/h) | 93.24 mph (150.05 km/h) |
| 2.35 | 2.73 | 2.94 | 3.07 | 3.21 | 3.31 | 3.42 | 3.55 | 3.73 | 3.91 | 4.11 | 4.27 | 4.56 | 4.88 | 5.13 | 5.29 | 5.38 | 5.71 | 6.17 | 7.17 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1949 | 2265 | 2439 | 2547 | 2663 | 2746 | 2837 | 2945 | 3094 | 3244 | 3410 | 3542 | 3783 | 4048 | 4256 | 4388 | 4463 | 4737 | 5118 | 5948 |
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