Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 315/35-21 | 305/30-21 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 29.68 (753.9) | 28.2 (716.4) | -1.48 (-37.5) -5% |
| Width inches (mm) | 12.4 (315) | 12.01 (305) | -0.39 (-10) -3.2% |
| Circum. inches (mm) | 93.25 (2368.45) | 88.61 (2250.64) | -4.64 (-117.81) -5% |
| Sidewall Height inches (mm) | 4.34 (110.25) | 3.6 (91.5) | -0.74 (-18.75) -17% |
| Revolutions per mile (km) | 679.49 (422.22) | 715.06 (444.32) | 35.57 (22.1) 5.2% |
305/30-21 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 19.01 mph (30.59 km/h) |
| 25 mph (40.23 km/h) | 23.76 mph (38.23 km/h) |
| 30 mph (48.28 km/h) | 28.51 mph (45.88 km/h) |
| 35 mph (56.33 km/h) | 33.26 mph (53.53 km/h) |
| 40 mph (64.37 km/h) | 38.01 mph (61.17 km/h) |
| 45 mph (72.42 km/h) | 42.76 mph (68.82 km/h) |
| 50 mph (80.47 km/h) | 47.51 mph (76.46 km/h) |
| 55 mph (88.51 km/h) | 52.26 mph (84.11 km/h) |
| 60 mph (96.56 km/h) | 57.02 mph (91.76 km/h) |
| 65 mph (104.61 km/h) | 61.77 mph (99.4 km/h) |
| 70 mph (112.65 km/h) | 66.52 mph (107.05 km/h) |
| 75 mph (120.7 km/h) | 71.27 mph (114.7 km/h) |
| 80 mph (128.75 km/h) | 76.02 mph (122.34 km/h) |
| 85 mph (136.79 km/h) | 80.77 mph (129.99 km/h) |
| 90 mph (144.84 km/h) | 85.52 mph (137.64 km/h) |
| 95 mph (152.89 km/h) | 90.27 mph (145.28 km/h) |
| 100 mph (160.93 km/h) | 95.03 mph (152.93 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1820 | 2114 | 2277 | 2377 | 2486 | 2563 | 2648 | 2749 | 2888 | 3028 | 3183 | 3306 | 3531 | 3779 | 3972 | 4096 | 4166 | 4421 | 4778 | 5552 |
Better Fuel Economy Factory Ratios Increased Power
