Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 275/40-21 | 255/40-21 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 29.66 (753.4) | 29.03 (737.4) | -0.63 (-16) -2.1% |
| Width inches (mm) | 10.83 (275) | 10.04 (255) | -0.79 (-20) -7.3% |
| Circum. inches (mm) | 93.18 (2366.88) | 91.21 (2316.61) | -1.98 (-50.27) -2.1% |
| Sidewall Height inches (mm) | 4.33 (110) | 4.02 (102) | -0.31 (-8) -7.3% |
| Revolutions per mile (km) | 679.94 (422.5) | 694.7 (431.66) | 14.75 (9.17) 2.2% |
255/40-21 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 19.58 mph (31.5 km/h) |
| 25 mph (40.23 km/h) | 24.47 mph (39.38 km/h) |
| 30 mph (48.28 km/h) | 29.36 mph (47.26 km/h) |
| 35 mph (56.33 km/h) | 34.26 mph (55.13 km/h) |
| 40 mph (64.37 km/h) | 39.15 mph (63.01 km/h) |
| 45 mph (72.42 km/h) | 44.04 mph (70.88 km/h) |
| 50 mph (80.47 km/h) | 48.94 mph (78.76 km/h) |
| 55 mph (88.51 km/h) | 53.83 mph (86.63 km/h) |
| 60 mph (96.56 km/h) | 58.73 mph (94.51 km/h) |
| 65 mph (104.61 km/h) | 63.62 mph (102.39 km/h) |
| 70 mph (112.65 km/h) | 68.51 mph (110.26 km/h) |
| 75 mph (120.7 km/h) | 73.41 mph (118.14 km/h) |
| 80 mph (128.75 km/h) | 78.3 mph (126.01 km/h) |
| 85 mph (136.79 km/h) | 83.19 mph (133.89 km/h) |
| 90 mph (144.84 km/h) | 88.09 mph (141.77 km/h) |
| 95 mph (152.89 km/h) | 92.98 mph (149.64 km/h) |
| 100 mph (160.93 km/h) | 97.88 mph (157.52 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 | 2054 | 2212 | 2310 | 2415 | 2490 | 2573 | 2671 | 2806 | 2941 | 3092 | 3212 | 3430 | 3671 | 3859 | 3980 | 4047 | 4296 | 4642 | 5394 |
Better Fuel Economy Factory Ratios Increased Power
