Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 255/40-21 | 245/45-21 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 29.03 (737.4) | 29.68 (753.9) | 0.65 (16.5) 2.2% |
| Width inches (mm) | 10.04 (255) | 9.65 (245) | -0.39 (-10) -3.9% |
| Circum. inches (mm) | 91.21 (2316.61) | 93.25 (2368.45) | 2.04 (51.84) 2.2% |
| Sidewall Height inches (mm) | 4.02 (102) | 4.34 (110.25) | 0.32 (8.25) 8.1% |
| Revolutions per mile (km) | 694.7 (431.66) | 679.49 (422.22) | -15.2 (-9.45) -2.2% |
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 20.45 mph (32.91 km/h) |
| 25 mph (40.23 km/h) | 25.56 mph (41.13 km/h) |
| 30 mph (48.28 km/h) | 30.67 mph (49.36 km/h) |
| 35 mph (56.33 km/h) | 35.78 mph (57.59 km/h) |
| 40 mph (64.37 km/h) | 40.9 mph (65.81 km/h) |
| 45 mph (72.42 km/h) | 46.01 mph (74.04 km/h) |
| 50 mph (80.47 km/h) | 51.12 mph (82.27 km/h) |
| 55 mph (88.51 km/h) | 56.23 mph (90.49 km/h) |
| 60 mph (96.56 km/h) | 61.34 mph (98.72 km/h) |
| 65 mph (104.61 km/h) | 66.45 mph (106.95 km/h) |
| 70 mph (112.65 km/h) | 71.57 mph (115.18 km/h) |
| 75 mph (120.7 km/h) | 76.68 mph (123.4 km/h) |
| 80 mph (128.75 km/h) | 81.79 mph (131.63 km/h) |
| 85 mph (136.79 km/h) | 86.9 mph (139.86 km/h) |
| 90 mph (144.84 km/h) | 92.01 mph (148.08 km/h) |
| 95 mph (152.89 km/h) | 97.13 mph (156.31 km/h) |
| 100 mph (160.93 km/h) | 102.24 mph (164.54 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1729 | 2009 | 2163 | 2259 | 2362 | 2436 | 2517 | 2612 | 2745 | 2877 | 3024 | 3142 | 3355 | 3591 | 3775 | 3892 | 3959 | 4202 | 4540 | 5276 |
Better Fuel Economy Factory Ratios Increased Power
