Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 185/65-15 | 235/40-18 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 24.47 (621.5) | 25.4 (645.2) | 0.93 (23.7) 3.8% |
| Width inches (mm) | 7.28 (185) | 9.25 (235) | 1.97 (50) 27% |
| Circum. inches (mm) | 76.87 (1952.5) | 79.8 (2026.96) | 2.93 (74.46) 3.8% |
| Sidewall Height inches (mm) | 4.73 (120.25) | 3.7 (94) | -1.03 (-26.25) -21.8% |
| Revolutions per mile (km) | 824.25 (512.16) | 793.97 (493.35) | -30.28 (-18.81) -3.7% |
235/40-18 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 20.76 mph (33.41 km/h) |
| 25 mph (40.23 km/h) | 25.95 mph (41.77 km/h) |
| 30 mph (48.28 km/h) | 31.14 mph (50.12 km/h) |
| 35 mph (56.33 km/h) | 36.33 mph (58.48 km/h) |
| 40 mph (64.37 km/h) | 41.53 mph (66.83 km/h) |
| 45 mph (72.42 km/h) | 46.72 mph (75.18 km/h) |
| 50 mph (80.47 km/h) | 51.91 mph (83.54 km/h) |
| 55 mph (88.51 km/h) | 57.1 mph (91.89 km/h) |
| 60 mph (96.56 km/h) | 62.29 mph (100.24 km/h) |
| 65 mph (104.61 km/h) | 67.48 mph (108.6 km/h) |
| 70 mph (112.65 km/h) | 72.67 mph (116.95 km/h) |
| 75 mph (120.7 km/h) | 77.86 mph (125.3 km/h) |
| 80 mph (128.75 km/h) | 83.05 mph (133.66 km/h) |
| 85 mph (136.79 km/h) | 88.24 mph (142.01 km/h) |
| 90 mph (144.84 km/h) | 93.43 mph (150.36 km/h) |
| 95 mph (152.89 km/h) | 98.62 mph (158.72 km/h) |
| 100 mph (160.93 km/h) | 103.81 mph (167.07 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2021 | 2347 | 2528 | 2640 | 2760 | 2846 | 2940 | 3052 | 3207 | 3362 | 3534 | 3671 | 3921 | 4196 | 4411 | 4548 | 4626 | 4909 | 5305 | 6165 |
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