Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 275/45-21 | 315/40-20 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 30.74 (780.9) | 29.92 (760) | -0.82 (-20.9) -2.7% |
| Width inches (mm) | 10.83 (275) | 12.4 (315) | 1.57 (40) 14.5% |
| Circum. inches (mm) | 96.59 (2453.27) | 94 (2387.61) | -2.59 (-65.66) -2.7% |
| Sidewall Height inches (mm) | 4.87 (123.75) | 4.96 (126) | 0.09 (2.25) 1.8% |
| Revolutions per mile (km) | 656 (407.62) | 674.04 (418.83) | 18.04 (11.21) 2.8% |
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 19.46 mph (31.33 km/h) |
| 25 mph (40.23 km/h) | 24.33 mph (39.16 km/h) |
| 30 mph (48.28 km/h) | 29.2 mph (46.99 km/h) |
| 35 mph (56.33 km/h) | 34.06 mph (54.82 km/h) |
| 40 mph (64.37 km/h) | 38.93 mph (62.65 km/h) |
| 45 mph (72.42 km/h) | 43.8 mph (70.48 km/h) |
| 50 mph (80.47 km/h) | 48.66 mph (78.31 km/h) |
| 55 mph (88.51 km/h) | 53.53 mph (86.15 km/h) |
| 60 mph (96.56 km/h) | 58.39 mph (93.98 km/h) |
| 65 mph (104.61 km/h) | 63.26 mph (101.81 km/h) |
| 70 mph (112.65 km/h) | 68.13 mph (109.64 km/h) |
| 75 mph (120.7 km/h) | 72.99 mph (117.47 km/h) |
| 80 mph (128.75 km/h) | 77.86 mph (125.3 km/h) |
| 85 mph (136.79 km/h) | 82.73 mph (133.13 km/h) |
| 90 mph (144.84 km/h) | 87.59 mph (140.96 km/h) |
| 95 mph (152.89 km/h) | 92.46 mph (148.8 km/h) |
| 100 mph (160.93 km/h) | 97.32 mph (156.63 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1715 | 1993 | 2146 | 2241 | 2343 | 2416 | 2496 | 2591 | 2723 | 2854 | 3000 | 3117 | 3328 | 3562 | 3744 | 3861 | 3927 | 4168 | 4504 | 5233 |
Better Fuel Economy Factory Ratios Increased Power
