Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 315/35-21 | 325/30-21 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 29.68 (753.9) | 28.68 (728.4) | -1 (-25.5) -3.4% |
| Width inches (mm) | 12.4 (315) | 12.8 (325) | 0.39 (10) 3.2% |
| Circum. inches (mm) | 93.25 (2368.45) | 90.09 (2288.34) | -3.15 (-80.11) -3.4% |
| Sidewall Height inches (mm) | 4.34 (110.25) | 3.84 (97.5) | -0.5 (-12.75) -11.6% |
| Revolutions per mile (km) | 679.49 (422.22) | 703.28 (437) | 23.79 (14.78) 3.5% |
325/30-21 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 19.32 mph (31.1 km/h) |
| 25 mph (40.23 km/h) | 24.15 mph (38.87 km/h) |
| 30 mph (48.28 km/h) | 28.99 mph (46.65 km/h) |
| 35 mph (56.33 km/h) | 33.82 mph (54.42 km/h) |
| 40 mph (64.37 km/h) | 38.65 mph (62.2 km/h) |
| 45 mph (72.42 km/h) | 43.48 mph (69.97 km/h) |
| 50 mph (80.47 km/h) | 48.31 mph (77.75 km/h) |
| 55 mph (88.51 km/h) | 53.14 mph (85.52 km/h) |
| 60 mph (96.56 km/h) | 57.97 mph (93.29 km/h) |
| 65 mph (104.61 km/h) | 62.8 mph (101.07 km/h) |
| 70 mph (112.65 km/h) | 67.63 mph (108.84 km/h) |
| 75 mph (120.7 km/h) | 72.46 mph (116.62 km/h) |
| 80 mph (128.75 km/h) | 77.29 mph (124.39 km/h) |
| 85 mph (136.79 km/h) | 82.12 mph (132.17 km/h) |
| 90 mph (144.84 km/h) | 86.96 mph (139.94 km/h) |
| 95 mph (152.89 km/h) | 91.79 mph (147.72 km/h) |
| 100 mph (160.93 km/h) | 96.62 mph (155.49 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1790 | 2079 | 2239 | 2338 | 2445 | 2521 | 2605 | 2704 | 2841 | 2978 | 3130 | 3252 | 3473 | 3717 | 3907 | 4029 | 4097 | 4349 | 4699 | 5461 |
Better Fuel Economy Factory Ratios Increased Power
