Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 165/90-18 | 255/45-20 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 29.69 (754.2) | 29.04 (737.5) | -0.66 (-16.7) -2.2% |
| Width inches (mm) | 6.5 (165) | 10.04 (255) | 3.54 (90) 54.5% |
| Circum. inches (mm) | 93.28 (2369.39) | 91.22 (2316.92) | -2.07 (-52.46) -2.2% |
| Sidewall Height inches (mm) | 5.85 (148.5) | 4.52 (114.75) | -1.33 (-33.75) -22.7% |
| Revolutions per mile (km) | 679.22 (422.05) | 694.6 (431.61) | 15.38 (9.56) 2.3% |
255/45-20 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 19.56 mph (31.47 km/h) |
| 25 mph (40.23 km/h) | 24.45 mph (39.34 km/h) |
| 30 mph (48.28 km/h) | 29.34 mph (47.21 km/h) |
| 35 mph (56.33 km/h) | 34.23 mph (55.08 km/h) |
| 40 mph (64.37 km/h) | 39.11 mph (62.95 km/h) |
| 45 mph (72.42 km/h) | 44 mph (70.82 km/h) |
| 50 mph (80.47 km/h) | 48.89 mph (78.69 km/h) |
| 55 mph (88.51 km/h) | 53.78 mph (86.55 km/h) |
| 60 mph (96.56 km/h) | 58.67 mph (94.42 km/h) |
| 65 mph (104.61 km/h) | 63.56 mph (102.29 km/h) |
| 70 mph (112.65 km/h) | 68.45 mph (110.16 km/h) |
| 75 mph (120.7 km/h) | 73.34 mph (118.03 km/h) |
| 80 mph (128.75 km/h) | 78.23 mph (125.9 km/h) |
| 85 mph (136.79 km/h) | 83.12 mph (133.77 km/h) |
| 90 mph (144.84 km/h) | 88.01 mph (141.63 km/h) |
| 95 mph (152.89 km/h) | 92.9 mph (149.5 km/h) |
| 100 mph (160.93 km/h) | 97.79 mph (157.37 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1768 | 2053 | 2211 | 2309 | 2415 | 2490 | 2572 | 2670 | 2806 | 2941 | 3091 | 3212 | 3430 | 3671 | 3859 | 3979 | 4047 | 4295 | 4641 | 5393 |
Better Fuel Economy Factory Ratios Increased Power
