Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 155/90-18 | 255/40-20 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 28.98 (736.2) | 28.03 (712) | -0.95 (-24.2) -3.3% |
| Width inches (mm) | 6.1 (155) | 10.04 (255) | 3.94 (100) 64.5% |
| Circum. inches (mm) | 91.06 (2312.84) | 88.06 (2236.81) | -2.99 (-76.03) -3.3% |
| Sidewall Height inches (mm) | 5.49 (139.5) | 4.02 (102) | -1.48 (-37.5) -26.9% |
| Revolutions per mile (km) | 695.83 (432.37) | 719.48 (447.06) | 23.65 (14.7) 3.4% |
255/40-20 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 19.34 mph (31.13 km/h) |
| 25 mph (40.23 km/h) | 24.18 mph (38.91 km/h) |
| 30 mph (48.28 km/h) | 29.01 mph (46.69 km/h) |
| 35 mph (56.33 km/h) | 33.85 mph (54.48 km/h) |
| 40 mph (64.37 km/h) | 38.69 mph (62.26 km/h) |
| 45 mph (72.42 km/h) | 43.52 mph (70.04 km/h) |
| 50 mph (80.47 km/h) | 48.36 mph (77.82 km/h) |
| 55 mph (88.51 km/h) | 53.19 mph (85.6 km/h) |
| 60 mph (96.56 km/h) | 58.03 mph (93.39 km/h) |
| 65 mph (104.61 km/h) | 62.86 mph (101.17 km/h) |
| 70 mph (112.65 km/h) | 67.7 mph (108.95 km/h) |
| 75 mph (120.7 km/h) | 72.53 mph (116.73 km/h) |
| 80 mph (128.75 km/h) | 77.37 mph (124.52 km/h) |
| 85 mph (136.79 km/h) | 82.21 mph (132.3 km/h) |
| 90 mph (144.84 km/h) | 87.04 mph (140.08 km/h) |
| 95 mph (152.89 km/h) | 91.88 mph (147.86 km/h) |
| 100 mph (160.93 km/h) | 96.71 mph (155.64 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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