Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 325/40-18 | 235/40-18 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 28.24 (717.2) | 25.4 (645.2) | -2.83 (-72) -10% |
| Width inches (mm) | 12.8 (325) | 9.25 (235) | -3.54 (-90) -27.7% |
| Circum. inches (mm) | 88.71 (2253.15) | 79.8 (2026.96) | -8.91 (-226.19) -10% |
| Sidewall Height inches (mm) | 5.12 (130) | 3.7 (94) | -1.42 (-36) -27.7% |
| Revolutions per mile (km) | 714.26 (443.82) | 793.97 (493.35) | 79.71 (49.53) 11.2% |
235/40-18 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 17.99 mph (28.96 km/h) |
| 25 mph (40.23 km/h) | 22.49 mph (36.19 km/h) |
| 30 mph (48.28 km/h) | 26.99 mph (43.43 km/h) |
| 35 mph (56.33 km/h) | 31.49 mph (50.67 km/h) |
| 40 mph (64.37 km/h) | 35.98 mph (57.91 km/h) |
| 45 mph (72.42 km/h) | 40.48 mph (65.15 km/h) |
| 50 mph (80.47 km/h) | 44.98 mph (72.39 km/h) |
| 55 mph (88.51 km/h) | 49.48 mph (79.63 km/h) |
| 60 mph (96.56 km/h) | 53.98 mph (86.87 km/h) |
| 65 mph (104.61 km/h) | 58.47 mph (94.11 km/h) |
| 70 mph (112.65 km/h) | 62.97 mph (101.34 km/h) |
| 75 mph (120.7 km/h) | 67.47 mph (108.58 km/h) |
| 80 mph (128.75 km/h) | 71.97 mph (115.82 km/h) |
| 85 mph (136.79 km/h) | 76.47 mph (123.06 km/h) |
| 90 mph (144.84 km/h) | 80.96 mph (130.3 km/h) |
| 95 mph (152.89 km/h) | 85.46 mph (137.54 km/h) |
| 100 mph (160.93 km/h) | 89.96 mph (144.78 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2021 | 2347 | 2528 | 2640 | 2760 | 2846 | 2940 | 3052 | 3207 | 3362 | 3534 | 3671 | 3921 | 4196 | 4411 | 4548 | 4626 | 4909 | 5305 | 6165 |
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