Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 145/85-18 | 235/45-21 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 27.7 (703.7) | 29.33 (744.9) | 1.62 (41.2) 5.9% |
| Width inches (mm) | 5.71 (145) | 9.25 (235) | 3.54 (90) 62.1% |
| Circum. inches (mm) | 87.04 (2210.74) | 92.13 (2340.17) | 5.1 (129.43) 5.9% |
| Sidewall Height inches (mm) | 4.85 (123.25) | 4.16 (105.75) | -0.69 (-17.5) -14.2% |
| Revolutions per mile (km) | 727.97 (452.34) | 687.7 (427.32) | -40.26 (-25.02) -5.5% |
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 21.17 mph (34.07 km/h) |
| 25 mph (40.23 km/h) | 26.46 mph (42.59 km/h) |
| 30 mph (48.28 km/h) | 31.76 mph (51.11 km/h) |
| 35 mph (56.33 km/h) | 37.05 mph (59.62 km/h) |
| 40 mph (64.37 km/h) | 42.34 mph (68.14 km/h) |
| 45 mph (72.42 km/h) | 47.63 mph (76.66 km/h) |
| 50 mph (80.47 km/h) | 52.93 mph (85.18 km/h) |
| 55 mph (88.51 km/h) | 58.22 mph (93.7 km/h) |
| 60 mph (96.56 km/h) | 63.51 mph (102.21 km/h) |
| 65 mph (104.61 km/h) | 68.81 mph (110.73 km/h) |
| 70 mph (112.65 km/h) | 74.1 mph (119.25 km/h) |
| 75 mph (120.7 km/h) | 79.39 mph (127.77 km/h) |
| 80 mph (128.75 km/h) | 84.68 mph (136.29 km/h) |
| 85 mph (136.79 km/h) | 89.98 mph (144.8 km/h) |
| 90 mph (144.84 km/h) | 95.27 mph (153.32 km/h) |
| 95 mph (152.89 km/h) | 100.56 mph (161.84 km/h) |
| 100 mph (160.93 km/h) | 105.85 mph (170.36 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1750 | 2033 | 2189 | 2286 | 2391 | 2465 | 2547 | 2644 | 2778 | 2912 | 3061 | 3180 | 3396 | 3634 | 3820 | 3940 | 4007 | 4252 | 4595 | 5340 |
Better Fuel Economy Factory Ratios Increased Power
