Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 305/40-23 | 315/40-21 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 32.61 (828.2) | 30.92 (785.4) | -1.69 (-42.8) -5.2% |
| Width inches (mm) | 12.01 (305) | 12.4 (315) | 0.39 (10) 3.3% |
| Circum. inches (mm) | 102.44 (2601.87) | 97.14 (2467.41) | -5.29 (-134.46) -5.2% |
| Sidewall Height inches (mm) | 4.8 (122) | 4.96 (126) | 0.16 (4) 3.3% |
| Revolutions per mile (km) | 618.53 (384.34) | 652.24 (405.28) | 33.71 (20.94) 5.4% |
315/40-21 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 18.97 mph (30.52 km/h) |
| 25 mph (40.23 km/h) | 23.71 mph (38.15 km/h) |
| 30 mph (48.28 km/h) | 28.45 mph (45.79 km/h) |
| 35 mph (56.33 km/h) | 33.19 mph (53.42 km/h) |
| 40 mph (64.37 km/h) | 37.93 mph (61.05 km/h) |
| 45 mph (72.42 km/h) | 42.67 mph (68.68 km/h) |
| 50 mph (80.47 km/h) | 47.42 mph (76.31 km/h) |
| 55 mph (88.51 km/h) | 52.16 mph (83.94 km/h) |
| 60 mph (96.56 km/h) | 56.9 mph (91.57 km/h) |
| 65 mph (104.61 km/h) | 61.64 mph (99.2 km/h) |
| 70 mph (112.65 km/h) | 66.38 mph (106.83 km/h) |
| 75 mph (120.7 km/h) | 71.12 mph (114.46 km/h) |
| 80 mph (128.75 km/h) | 75.87 mph (122.09 km/h) |
| 85 mph (136.79 km/h) | 80.61 mph (129.73 km/h) |
| 90 mph (144.84 km/h) | 85.35 mph (137.36 km/h) |
| 95 mph (152.89 km/h) | 90.09 mph (144.99 km/h) |
| 100 mph (160.93 km/h) | 94.83 mph (152.62 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1660 | 1928 | 2077 | 2168 | 2267 | 2338 | 2416 | 2507 | 2635 | 2762 | 2903 | 3016 | 3221 | 3447 | 3623 | 3736 | 3800 | 4033 | 4358 | 5064 |
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