Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 125/90-15 | 235/40-18 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 23.86 (606) | 25.4 (645.2) | 1.54 (39.2) 6.5% |
| Width inches (mm) | 4.92 (125) | 9.25 (235) | 4.33 (110) 88% |
| Circum. inches (mm) | 74.95 (1903.81) | 79.8 (2026.96) | 4.85 (123.15) 6.5% |
| Sidewall Height inches (mm) | 4.43 (112.5) | 3.7 (94) | -0.73 (-18.5) -16.4% |
| Revolutions per mile (km) | 845.33 (525.26) | 793.97 (493.35) | -51.36 (-31.91) -6.1% |
235/40-18 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 21.29 mph (34.27 km/h) |
| 25 mph (40.23 km/h) | 26.62 mph (42.84 km/h) |
| 30 mph (48.28 km/h) | 31.94 mph (51.4 km/h) |
| 35 mph (56.33 km/h) | 37.26 mph (59.97 km/h) |
| 40 mph (64.37 km/h) | 42.59 mph (68.54 km/h) |
| 45 mph (72.42 km/h) | 47.91 mph (77.11 km/h) |
| 50 mph (80.47 km/h) | 53.23 mph (85.67 km/h) |
| 55 mph (88.51 km/h) | 58.56 mph (94.24 km/h) |
| 60 mph (96.56 km/h) | 63.88 mph (102.81 km/h) |
| 65 mph (104.61 km/h) | 69.2 mph (111.37 km/h) |
| 70 mph (112.65 km/h) | 74.53 mph (119.94 km/h) |
| 75 mph (120.7 km/h) | 79.85 mph (128.51 km/h) |
| 80 mph (128.75 km/h) | 85.17 mph (137.08 km/h) |
| 85 mph (136.79 km/h) | 90.5 mph (145.64 km/h) |
| 90 mph (144.84 km/h) | 95.82 mph (154.21 km/h) |
| 95 mph (152.89 km/h) | 101.15 mph (162.78 km/h) |
| 100 mph (160.93 km/h) | 106.47 mph (171.35 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
