Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 225/30-20 | 225/40-18 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 25.31 (643) | 25.09 (637.2) | -0.23 (-5.8) -0.9% |
| Width inches (mm) | 8.86 (225) | 8.86 (225) | 0 (0) 0% |
| Circum. inches (mm) | 79.53 (2020.04) | 78.81 (2001.82) | -0.72 (-18.22) -0.9% |
| Sidewall Height inches (mm) | 2.66 (67.5) | 3.54 (90) | 0.89 (22.5) 33.3% |
| Revolutions per mile (km) | 796.69 (495.04) | 803.94 (499.54) | 7.25 (4.51) 0.9% |
225/40-18 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 19.82 mph (31.9 km/h) |
| 25 mph (40.23 km/h) | 24.77 mph (39.87 km/h) |
| 30 mph (48.28 km/h) | 29.73 mph (47.84 km/h) |
| 35 mph (56.33 km/h) | 34.68 mph (55.82 km/h) |
| 40 mph (64.37 km/h) | 39.64 mph (63.79 km/h) |
| 45 mph (72.42 km/h) | 44.59 mph (71.77 km/h) |
| 50 mph (80.47 km/h) | 49.55 mph (79.74 km/h) |
| 55 mph (88.51 km/h) | 54.5 mph (87.72 km/h) |
| 60 mph (96.56 km/h) | 59.46 mph (95.69 km/h) |
| 65 mph (104.61 km/h) | 64.41 mph (103.66 km/h) |
| 70 mph (112.65 km/h) | 69.37 mph (111.64 km/h) |
| 75 mph (120.7 km/h) | 74.32 mph (119.61 km/h) |
| 80 mph (128.75 km/h) | 79.28 mph (127.59 km/h) |
| 85 mph (136.79 km/h) | 84.23 mph (135.56 km/h) |
| 90 mph (144.84 km/h) | 89.19 mph (143.53 km/h) |
| 95 mph (152.89 km/h) | 94.14 mph (151.51 km/h) |
| 100 mph (160.93 km/h) | 99.1 mph (159.48 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2046 | 2377 | 2560 | 2673 | 2795 | 2882 | 2977 | 3091 | 3247 | 3404 | 3578 | 3717 | 3970 | 4248 | 4466 | 4605 | 4684 | 4971 | 5372 | 6242 |
Better Fuel Economy Factory Ratios Increased Power
