Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 145/70-18 | 235/45-18 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 25.99 (660.2) | 26.33 (668.7) | 0.33 (8.5) 1.3% |
| Width inches (mm) | 5.71 (145) | 9.25 (235) | 3.54 (90) 62.1% |
| Circum. inches (mm) | 81.66 (2074.08) | 82.71 (2100.78) | 1.05 (26.7) 1.3% |
| Sidewall Height inches (mm) | 4 (101.5) | 4.16 (105.75) | 0.17 (4.25) 4.2% |
| Revolutions per mile (km) | 775.93 (482.14) | 766.07 (476.01) | -9.86 (-6.13) -1.3% |
235/45-18 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 20.26 mph (32.6 km/h) |
| 25 mph (40.23 km/h) | 25.32 mph (40.75 km/h) |
| 30 mph (48.28 km/h) | 30.39 mph (48.9 km/h) |
| 35 mph (56.33 km/h) | 35.45 mph (57.05 km/h) |
| 40 mph (64.37 km/h) | 40.51 mph (65.2 km/h) |
| 45 mph (72.42 km/h) | 45.58 mph (73.35 km/h) |
| 50 mph (80.47 km/h) | 50.64 mph (81.5 km/h) |
| 55 mph (88.51 km/h) | 55.71 mph (89.65 km/h) |
| 60 mph (96.56 km/h) | 60.77 mph (97.8 km/h) |
| 65 mph (104.61 km/h) | 65.84 mph (105.95 km/h) |
| 70 mph (112.65 km/h) | 70.9 mph (114.1 km/h) |
| 75 mph (120.7 km/h) | 75.97 mph (122.26 km/h) |
| 80 mph (128.75 km/h) | 81.03 mph (130.41 km/h) |
| 85 mph (136.79 km/h) | 86.09 mph (138.56 km/h) |
| 90 mph (144.84 km/h) | 91.16 mph (146.71 km/h) |
| 95 mph (152.89 km/h) | 96.22 mph (154.86 km/h) |
| 100 mph (160.93 km/h) | 101.29 mph (163.01 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
