Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 225/40-18 | 235/45-18 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 25.09 (637.2) | 26.33 (668.7) | 1.24 (31.5) 4.9% |
| Width inches (mm) | 8.86 (225) | 9.25 (235) | 0.39 (10) 4.4% |
| Circum. inches (mm) | 78.81 (2001.82) | 82.71 (2100.78) | 3.9 (98.96) 4.9% |
| Sidewall Height inches (mm) | 3.54 (90) | 4.16 (105.75) | 0.62 (15.75) 17.5% |
| Revolutions per mile (km) | 803.94 (499.54) | 766.07 (476.01) | -37.87 (-23.53) -4.7% |
235/45-18 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 20.99 mph (33.78 km/h) |
| 25 mph (40.23 km/h) | 26.24 mph (42.22 km/h) |
| 30 mph (48.28 km/h) | 31.48 mph (50.67 km/h) |
| 35 mph (56.33 km/h) | 36.73 mph (59.11 km/h) |
| 40 mph (64.37 km/h) | 41.98 mph (67.56 km/h) |
| 45 mph (72.42 km/h) | 47.22 mph (76 km/h) |
| 50 mph (80.47 km/h) | 52.47 mph (84.45 km/h) |
| 55 mph (88.51 km/h) | 57.72 mph (92.89 km/h) |
| 60 mph (96.56 km/h) | 62.97 mph (101.33 km/h) |
| 65 mph (104.61 km/h) | 68.21 mph (109.78 km/h) |
| 70 mph (112.65 km/h) | 73.46 mph (118.22 km/h) |
| 75 mph (120.7 km/h) | 78.71 mph (126.67 km/h) |
| 80 mph (128.75 km/h) | 83.95 mph (135.11 km/h) |
| 85 mph (136.79 km/h) | 89.2 mph (143.56 km/h) |
| 90 mph (144.84 km/h) | 94.45 mph (152 km/h) |
| 95 mph (152.89 km/h) | 99.7 mph (160.45 km/h) |
| 100 mph (160.93 km/h) | 104.94 mph (168.89 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 |
Better Fuel Economy Factory Ratios Increased Power
