Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 315/35-21 | 255/30-21 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 29.68 (753.9) | 27.02 (686.4) | -2.66 (-67.5) -9% |
| Width inches (mm) | 12.4 (315) | 10.04 (255) | -2.36 (-60) -19% |
| Circum. inches (mm) | 93.25 (2368.45) | 84.9 (2156.39) | -8.35 (-212.06) -9% |
| Sidewall Height inches (mm) | 4.34 (110.25) | 3.01 (76.5) | -1.33 (-33.75) -30.6% |
| Revolutions per mile (km) | 679.49 (422.22) | 746.31 (463.74) | 66.82 (41.52) 9.8% |
255/30-21 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 18.21 mph (29.31 km/h) |
| 25 mph (40.23 km/h) | 22.76 mph (36.63 km/h) |
| 30 mph (48.28 km/h) | 27.31 mph (43.96 km/h) |
| 35 mph (56.33 km/h) | 31.87 mph (51.28 km/h) |
| 40 mph (64.37 km/h) | 36.42 mph (58.61 km/h) |
| 45 mph (72.42 km/h) | 40.97 mph (65.94 km/h) |
| 50 mph (80.47 km/h) | 45.52 mph (73.26 km/h) |
| 55 mph (88.51 km/h) | 50.08 mph (80.59 km/h) |
| 60 mph (96.56 km/h) | 54.63 mph (87.92 km/h) |
| 65 mph (104.61 km/h) | 59.18 mph (95.24 km/h) |
| 70 mph (112.65 km/h) | 63.73 mph (102.57 km/h) |
| 75 mph (120.7 km/h) | 68.28 mph (109.89 km/h) |
| 80 mph (128.75 km/h) | 72.84 mph (117.22 km/h) |
| 85 mph (136.79 km/h) | 77.39 mph (124.55 km/h) |
| 90 mph (144.84 km/h) | 81.94 mph (131.87 km/h) |
| 95 mph (152.89 km/h) | 86.49 mph (139.2 km/h) |
| 100 mph (160.93 km/h) | 91.05 mph (146.53 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1899 | 2206 | 2376 | 2481 | 2594 | 2675 | 2764 | 2869 | 3015 | 3160 | 3322 | 3451 | 3685 | 3944 | 4146 | 4275 | 4348 | 4615 | 4986 | 5795 |
Better Fuel Economy Factory Ratios Increased Power
