Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 275/55-20 | 390/40-17 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 31.91 (810.5) | 29.28 (743.8) | -2.63 (-66.7) -8.2% |
| Width inches (mm) | 10.83 (275) | 15.35 (390) | 4.53 (115) 41.8% |
| Circum. inches (mm) | 100.25 (2546.26) | 92 (2336.72) | -8.25 (-209.54) -8.2% |
| Sidewall Height inches (mm) | 5.95 (151.25) | 6.14 (156) | 0.19 (4.75) 3.1% |
| Revolutions per mile (km) | 632.04 (392.73) | 688.72 (427.95) | 56.68 (35.22) 9% |
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 18.35 mph (29.54 km/h) |
| 25 mph (40.23 km/h) | 22.94 mph (36.92 km/h) |
| 30 mph (48.28 km/h) | 27.53 mph (44.31 km/h) |
| 35 mph (56.33 km/h) | 32.12 mph (51.69 km/h) |
| 40 mph (64.37 km/h) | 36.71 mph (59.08 km/h) |
| 45 mph (72.42 km/h) | 41.3 mph (66.46 km/h) |
| 50 mph (80.47 km/h) | 45.89 mph (73.85 km/h) |
| 55 mph (88.51 km/h) | 50.47 mph (81.23 km/h) |
| 60 mph (96.56 km/h) | 55.06 mph (88.61 km/h) |
| 65 mph (104.61 km/h) | 59.65 mph (96 km/h) |
| 70 mph (112.65 km/h) | 64.24 mph (103.38 km/h) |
| 75 mph (120.7 km/h) | 68.83 mph (110.77 km/h) |
| 80 mph (128.75 km/h) | 73.42 mph (118.15 km/h) |
| 85 mph (136.79 km/h) | 78 mph (125.54 km/h) |
| 90 mph (144.84 km/h) | 82.59 mph (132.92 km/h) |
| 95 mph (152.89 km/h) | 87.18 mph (140.31 km/h) |
| 100 mph (160.93 km/h) | 91.77 mph (147.69 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1753 | 2036 | 2193 | 2290 | 2394 | 2469 | 2551 | 2648 | 2782 | 2916 | 3065 | 3185 | 3401 | 3640 | 3826 | 3945 | 4012 | 4259 | 4602 | 5347 |
Better Fuel Economy Factory Ratios Increased Power
