Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 235/40-18 | 235/45-18 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 25.4 (645.2) | 26.33 (668.7) | 0.93 (23.5) 3.6% |
| Width inches (mm) | 9.25 (235) | 9.25 (235) | 0 (0) 0% |
| Circum. inches (mm) | 79.8 (2026.96) | 82.71 (2100.78) | 2.91 (73.83) 3.6% |
| Sidewall Height inches (mm) | 3.7 (94) | 4.16 (105.75) | 0.46 (11.75) 12.5% |
| Revolutions per mile (km) | 793.97 (493.35) | 766.07 (476.01) | -27.9 (-17.34) -3.5% |
235/45-18 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 20.73 mph (33.36 km/h) |
| 25 mph (40.23 km/h) | 25.91 mph (41.7 km/h) |
| 30 mph (48.28 km/h) | 31.09 mph (50.04 km/h) |
| 35 mph (56.33 km/h) | 36.27 mph (58.38 km/h) |
| 40 mph (64.37 km/h) | 41.46 mph (66.72 km/h) |
| 45 mph (72.42 km/h) | 46.64 mph (75.06 km/h) |
| 50 mph (80.47 km/h) | 51.82 mph (83.4 km/h) |
| 55 mph (88.51 km/h) | 57 mph (91.74 km/h) |
| 60 mph (96.56 km/h) | 62.19 mph (100.08 km/h) |
| 65 mph (104.61 km/h) | 67.37 mph (108.42 km/h) |
| 70 mph (112.65 km/h) | 72.55 mph (116.76 km/h) |
| 75 mph (120.7 km/h) | 77.73 mph (125.1 km/h) |
| 80 mph (128.75 km/h) | 82.91 mph (133.44 km/h) |
| 85 mph (136.79 km/h) | 88.1 mph (141.78 km/h) |
| 90 mph (144.84 km/h) | 93.28 mph (150.12 km/h) |
| 95 mph (152.89 km/h) | 98.46 mph (158.46 km/h) |
| 100 mph (160.93 km/h) | 103.64 mph (166.8 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
