Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 285/35-21 | 325/30-21 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 28.85 (732.9) | 28.68 (728.4) | -0.18 (-4.5) -0.6% |
| Width inches (mm) | 11.22 (285) | 12.8 (325) | 1.57 (40) 14% |
| Circum. inches (mm) | 90.65 (2302.47) | 90.09 (2288.34) | -0.56 (-14.14) -0.6% |
| Sidewall Height inches (mm) | 3.93 (99.75) | 3.84 (97.5) | -0.09 (-2.25) -2.3% |
| Revolutions per mile (km) | 698.96 (434.31) | 703.28 (437) | 4.32 (2.68) 0.6% |
325/30-21 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 19.88 mph (31.99 km/h) |
| 25 mph (40.23 km/h) | 24.85 mph (39.99 km/h) |
| 30 mph (48.28 km/h) | 29.82 mph (47.98 km/h) |
| 35 mph (56.33 km/h) | 34.79 mph (55.98 km/h) |
| 40 mph (64.37 km/h) | 39.75 mph (63.98 km/h) |
| 45 mph (72.42 km/h) | 44.72 mph (71.98 km/h) |
| 50 mph (80.47 km/h) | 49.69 mph (79.97 km/h) |
| 55 mph (88.51 km/h) | 54.66 mph (87.97 km/h) |
| 60 mph (96.56 km/h) | 59.63 mph (95.97 km/h) |
| 65 mph (104.61 km/h) | 64.6 mph (103.97 km/h) |
| 70 mph (112.65 km/h) | 69.57 mph (111.96 km/h) |
| 75 mph (120.7 km/h) | 74.54 mph (119.96 km/h) |
| 80 mph (128.75 km/h) | 79.51 mph (127.96 km/h) |
| 85 mph (136.79 km/h) | 84.48 mph (135.95 km/h) |
| 90 mph (144.84 km/h) | 89.45 mph (143.95 km/h) |
| 95 mph (152.89 km/h) | 94.42 mph (151.95 km/h) |
| 100 mph (160.93 km/h) | 99.39 mph (159.95 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
