Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 255/30-21 | 235/20-21 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 27.02 (686.4) | 24.7 (627.4) | -2.32 (-59) -8.6% |
| Width inches (mm) | 10.04 (255) | 9.25 (235) | -0.79 (-20) -7.8% |
| Circum. inches (mm) | 84.9 (2156.39) | 77.6 (1971.04) | -7.3 (-185.35) -8.6% |
| Sidewall Height inches (mm) | 3.01 (76.5) | 1.85 (47) | -1.16 (-29.5) -38.6% |
| Revolutions per mile (km) | 746.31 (463.74) | 816.5 (507.35) | 70.18 (43.61) 9.4% |
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 18.28 mph (29.42 km/h) |
| 25 mph (40.23 km/h) | 22.85 mph (36.78 km/h) |
| 30 mph (48.28 km/h) | 27.42 mph (44.13 km/h) |
| 35 mph (56.33 km/h) | 31.99 mph (51.49 km/h) |
| 40 mph (64.37 km/h) | 36.56 mph (58.84 km/h) |
| 45 mph (72.42 km/h) | 41.13 mph (66.2 km/h) |
| 50 mph (80.47 km/h) | 45.7 mph (73.55 km/h) |
| 55 mph (88.51 km/h) | 50.27 mph (80.91 km/h) |
| 60 mph (96.56 km/h) | 54.84 mph (88.26 km/h) |
| 65 mph (104.61 km/h) | 59.41 mph (95.62 km/h) |
| 70 mph (112.65 km/h) | 63.98 mph (102.97 km/h) |
| 75 mph (120.7 km/h) | 68.55 mph (110.33 km/h) |
| 80 mph (128.75 km/h) | 73.12 mph (117.68 km/h) |
| 85 mph (136.79 km/h) | 77.69 mph (125.04 km/h) |
| 90 mph (144.84 km/h) | 82.26 mph (132.39 km/h) |
| 95 mph (152.89 km/h) | 86.83 mph (139.75 km/h) |
| 100 mph (160.93 km/h) | 91.4 mph (147.1 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2078 | 2414 | 2599 | 2714 | 2838 | 2927 | 3024 | 3139 | 3298 | 3457 | 3634 | 3775 | 4032 | 4315 | 4536 | 4677 | 4757 | 5049 | 5455 | 6340 |
Better Fuel Economy Factory Ratios Increased Power
