Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 285/40-21 | 315/35-21 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 29.98 (761.4) | 29.68 (753.9) | -0.3 (-7.5) -1% |
| Width inches (mm) | 11.22 (285) | 12.4 (315) | 1.18 (30) 10.5% |
| Circum. inches (mm) | 94.17 (2392.01) | 93.25 (2368.45) | -0.93 (-23.56) -1% |
| Sidewall Height inches (mm) | 4.49 (114) | 4.34 (110.25) | -0.15 (-3.75) -3.3% |
| Revolutions per mile (km) | 672.8 (418.06) | 679.49 (422.22) | 6.69 (4.16) 1% |
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 19.8 mph (31.87 km/h) |
| 25 mph (40.23 km/h) | 24.75 mph (39.84 km/h) |
| 30 mph (48.28 km/h) | 29.7 mph (47.8 km/h) |
| 35 mph (56.33 km/h) | 34.66 mph (55.77 km/h) |
| 40 mph (64.37 km/h) | 39.61 mph (63.74 km/h) |
| 45 mph (72.42 km/h) | 44.56 mph (71.71 km/h) |
| 50 mph (80.47 km/h) | 49.51 mph (79.67 km/h) |
| 55 mph (88.51 km/h) | 54.46 mph (87.64 km/h) |
| 60 mph (96.56 km/h) | 59.41 mph (95.61 km/h) |
| 65 mph (104.61 km/h) | 64.36 mph (103.58 km/h) |
| 70 mph (112.65 km/h) | 69.31 mph (111.54 km/h) |
| 75 mph (120.7 km/h) | 74.26 mph (119.51 km/h) |
| 80 mph (128.75 km/h) | 79.21 mph (127.48 km/h) |
| 85 mph (136.79 km/h) | 84.16 mph (135.45 km/h) |
| 90 mph (144.84 km/h) | 89.11 mph (143.41 km/h) |
| 95 mph (152.89 km/h) | 94.06 mph (151.38 km/h) |
| 100 mph (160.93 km/h) | 99.01 mph (159.35 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1729 | 2009 | 2163 | 2259 | 2362 | 2436 | 2517 | 2612 | 2745 | 2877 | 3024 | 3142 | 3355 | 3591 | 3775 | 3892 | 3959 | 4202 | 4540 | 5276 |
Better Fuel Economy Factory Ratios Increased Power
