Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 325/40-18 | 305/40-18 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 28.24 (717.2) | 27.61 (701.2) | -0.63 (-16) -2.2% |
| Width inches (mm) | 12.8 (325) | 12.01 (305) | -0.79 (-20) -6.2% |
| Circum. inches (mm) | 88.71 (2253.15) | 86.73 (2202.88) | -1.98 (-50.27) -2.2% |
| Sidewall Height inches (mm) | 5.12 (130) | 4.8 (122) | -0.31 (-8) -6.2% |
| Revolutions per mile (km) | 714.26 (443.82) | 730.56 (453.95) | 16.3 (10.13) 2.3% |
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 19.55 mph (31.47 km/h) |
| 25 mph (40.23 km/h) | 24.44 mph (39.34 km/h) |
| 30 mph (48.28 km/h) | 29.33 mph (47.2 km/h) |
| 35 mph (56.33 km/h) | 34.22 mph (55.07 km/h) |
| 40 mph (64.37 km/h) | 39.11 mph (62.94 km/h) |
| 45 mph (72.42 km/h) | 44 mph (70.8 km/h) |
| 50 mph (80.47 km/h) | 48.88 mph (78.67 km/h) |
| 55 mph (88.51 km/h) | 53.77 mph (86.54 km/h) |
| 60 mph (96.56 km/h) | 58.66 mph (94.41 km/h) |
| 65 mph (104.61 km/h) | 63.55 mph (102.27 km/h) |
| 70 mph (112.65 km/h) | 68.44 mph (110.14 km/h) |
| 75 mph (120.7 km/h) | 73.33 mph (118.01 km/h) |
| 80 mph (128.75 km/h) | 78.22 mph (125.88 km/h) |
| 85 mph (136.79 km/h) | 83.1 mph (133.74 km/h) |
| 90 mph (144.84 km/h) | 87.99 mph (141.61 km/h) |
| 95 mph (152.89 km/h) | 92.88 mph (149.48 km/h) |
| 100 mph (160.93 km/h) | 97.77 mph (157.34 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1859 | 2160 | 2326 | 2429 | 2540 | 2619 | 2706 | 2808 | 2951 | 3093 | 3252 | 3378 | 3608 | 3861 | 4058 | 4185 | 4256 | 4517 | 4881 | 5672 |
Better Fuel Economy Factory Ratios Increased Power
