Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 135/70-18 | 235/40-18 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 25.44 (646.2) | 25.4 (645.2) | -0.04 (-1) -0.2% |
| Width inches (mm) | 5.31 (135) | 9.25 (235) | 3.94 (100) 74.1% |
| Circum. inches (mm) | 79.93 (2030.1) | 79.8 (2026.96) | -0.12 (-3.14) -0.2% |
| Sidewall Height inches (mm) | 3.72 (94.5) | 3.7 (94) | -0.02 (-0.5) -0.5% |
| Revolutions per mile (km) | 792.74 (492.59) | 793.97 (493.35) | 1.23 (0.76) 0.2% |
235/40-18 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 19.97 mph (32.14 km/h) |
| 25 mph (40.23 km/h) | 24.96 mph (40.17 km/h) |
| 30 mph (48.28 km/h) | 29.95 mph (48.21 km/h) |
| 35 mph (56.33 km/h) | 34.95 mph (56.24 km/h) |
| 40 mph (64.37 km/h) | 39.94 mph (64.27 km/h) |
| 45 mph (72.42 km/h) | 44.93 mph (72.31 km/h) |
| 50 mph (80.47 km/h) | 49.92 mph (80.34 km/h) |
| 55 mph (88.51 km/h) | 54.91 mph (88.38 km/h) |
| 60 mph (96.56 km/h) | 59.91 mph (96.41 km/h) |
| 65 mph (104.61 km/h) | 64.9 mph (104.45 km/h) |
| 70 mph (112.65 km/h) | 69.89 mph (112.48 km/h) |
| 75 mph (120.7 km/h) | 74.88 mph (120.51 km/h) |
| 80 mph (128.75 km/h) | 79.88 mph (128.55 km/h) |
| 85 mph (136.79 km/h) | 84.87 mph (136.58 km/h) |
| 90 mph (144.84 km/h) | 89.86 mph (144.62 km/h) |
| 95 mph (152.89 km/h) | 94.85 mph (152.65 km/h) |
| 100 mph (160.93 km/h) | 99.85 mph (160.69 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 |
Better Fuel Economy Factory Ratios Increased Power
