Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 275/55-21 | 255/40-20 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 32.91 (835.9) | 28.03 (712) | -4.88 (-123.9) -14.8% |
| Width inches (mm) | 10.83 (275) | 10.04 (255) | -0.79 (-20) -7.3% |
| Circum. inches (mm) | 103.39 (2626.06) | 88.06 (2236.81) | -15.32 (-389.24) -14.8% |
| Sidewall Height inches (mm) | 5.95 (151.25) | 4.02 (102) | -1.94 (-49.25) -32.6% |
| Revolutions per mile (km) | 612.84 (380.8) | 719.48 (447.06) | 106.64 (66.27) 17.4% |
255/40-20 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 17.04 mph (27.42 km/h) |
| 25 mph (40.23 km/h) | 21.29 mph (34.27 km/h) |
| 30 mph (48.28 km/h) | 25.55 mph (41.12 km/h) |
| 35 mph (56.33 km/h) | 29.81 mph (47.98 km/h) |
| 40 mph (64.37 km/h) | 34.07 mph (54.83 km/h) |
| 45 mph (72.42 km/h) | 38.33 mph (61.69 km/h) |
| 50 mph (80.47 km/h) | 42.59 mph (68.54 km/h) |
| 55 mph (88.51 km/h) | 46.85 mph (75.39 km/h) |
| 60 mph (96.56 km/h) | 51.11 mph (82.25 km/h) |
| 65 mph (104.61 km/h) | 55.37 mph (89.1 km/h) |
| 70 mph (112.65 km/h) | 59.62 mph (95.96 km/h) |
| 75 mph (120.7 km/h) | 63.88 mph (102.81 km/h) |
| 80 mph (128.75 km/h) | 68.14 mph (109.66 km/h) |
| 85 mph (136.79 km/h) | 72.4 mph (116.52 km/h) |
| 90 mph (144.84 km/h) | 76.66 mph (123.37 km/h) |
| 95 mph (152.89 km/h) | 80.92 mph (130.23 km/h) |
| 100 mph (160.93 km/h) | 85.18 mph (137.08 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1831 | 2127 | 2291 | 2392 | 2501 | 2579 | 2665 | 2766 | 2906 | 3046 | 3202 | 3327 | 3553 | 3802 | 3997 | 4122 | 4192 | 4449 | 4807 | 5586 |
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