Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 145/85-18 | 235/45-18 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 27.7 (703.7) | 26.33 (668.7) | -1.38 (-35) -5% |
| Width inches (mm) | 5.71 (145) | 9.25 (235) | 3.54 (90) 62.1% |
| Circum. inches (mm) | 87.04 (2210.74) | 82.71 (2100.78) | -4.33 (-109.96) -5% |
| Sidewall Height inches (mm) | 4.85 (123.25) | 4.16 (105.75) | -0.69 (-17.5) -14.2% |
| Revolutions per mile (km) | 727.97 (452.34) | 766.07 (476.01) | 38.1 (23.68) 5.2% |
235/45-18 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 19.01 mph (30.59 km/h) |
| 25 mph (40.23 km/h) | 23.76 mph (38.23 km/h) |
| 30 mph (48.28 km/h) | 28.51 mph (45.88 km/h) |
| 35 mph (56.33 km/h) | 33.26 mph (53.53 km/h) |
| 40 mph (64.37 km/h) | 38.01 mph (61.17 km/h) |
| 45 mph (72.42 km/h) | 42.76 mph (68.82 km/h) |
| 50 mph (80.47 km/h) | 47.51 mph (76.47 km/h) |
| 55 mph (88.51 km/h) | 52.26 mph (84.11 km/h) |
| 60 mph (96.56 km/h) | 57.02 mph (91.76 km/h) |
| 65 mph (104.61 km/h) | 61.77 mph (99.4 km/h) |
| 70 mph (112.65 km/h) | 66.52 mph (107.05 km/h) |
| 75 mph (120.7 km/h) | 71.27 mph (114.7 km/h) |
| 80 mph (128.75 km/h) | 76.02 mph (122.34 km/h) |
| 85 mph (136.79 km/h) | 80.77 mph (129.99 km/h) |
| 90 mph (144.84 km/h) | 85.52 mph (137.64 km/h) |
| 95 mph (152.89 km/h) | 90.27 mph (145.28 km/h) |
| 100 mph (160.93 km/h) | 95.03 mph (152.93 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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