Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 185/65-15 | 225/40-18 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 24.47 (621.5) | 25.09 (637.2) | 0.62 (15.7) 2.5% |
| Width inches (mm) | 7.28 (185) | 8.86 (225) | 1.57 (40) 21.6% |
| Circum. inches (mm) | 76.87 (1952.5) | 78.81 (2001.82) | 1.94 (49.32) 2.5% |
| Sidewall Height inches (mm) | 4.73 (120.25) | 3.54 (90) | -1.19 (-30.25) -25.2% |
| Revolutions per mile (km) | 824.25 (512.16) | 803.94 (499.54) | -20.31 (-12.62) -2.5% |
225/40-18 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 20.51 mph (33 km/h) |
| 25 mph (40.23 km/h) | 25.63 mph (41.25 km/h) |
| 30 mph (48.28 km/h) | 30.76 mph (49.5 km/h) |
| 35 mph (56.33 km/h) | 35.88 mph (57.75 km/h) |
| 40 mph (64.37 km/h) | 41.01 mph (66 km/h) |
| 45 mph (72.42 km/h) | 46.14 mph (74.25 km/h) |
| 50 mph (80.47 km/h) | 51.26 mph (82.5 km/h) |
| 55 mph (88.51 km/h) | 56.39 mph (90.75 km/h) |
| 60 mph (96.56 km/h) | 61.52 mph (99 km/h) |
| 65 mph (104.61 km/h) | 66.64 mph (107.25 km/h) |
| 70 mph (112.65 km/h) | 71.77 mph (115.5 km/h) |
| 75 mph (120.7 km/h) | 76.89 mph (123.75 km/h) |
| 80 mph (128.75 km/h) | 82.02 mph (132 km/h) |
| 85 mph (136.79 km/h) | 87.15 mph (140.25 km/h) |
| 90 mph (144.84 km/h) | 92.27 mph (148.5 km/h) |
| 95 mph (152.89 km/h) | 97.4 mph (156.75 km/h) |
| 100 mph (160.93 km/h) | 102.53 mph (165 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
