Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 235/45-21 | 155/90-18 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 29.33 (744.9) | 28.98 (736.2) | -0.34 (-8.7) -1.2% |
| Width inches (mm) | 9.25 (235) | 6.1 (155) | -3.15 (-80) -34% |
| Circum. inches (mm) | 92.13 (2340.17) | 91.06 (2312.84) | -1.08 (-27.33) -1.2% |
| Sidewall Height inches (mm) | 4.16 (105.75) | 5.49 (139.5) | 1.33 (33.75) 31.9% |
| Revolutions per mile (km) | 687.7 (427.32) | 695.83 (432.37) | 8.13 (5.05) 1.2% |
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 19.77 mph (31.81 km/h) |
| 25 mph (40.23 km/h) | 24.71 mph (39.76 km/h) |
| 30 mph (48.28 km/h) | 29.65 mph (47.72 km/h) |
| 35 mph (56.33 km/h) | 34.59 mph (55.67 km/h) |
| 40 mph (64.37 km/h) | 39.53 mph (63.62 km/h) |
| 45 mph (72.42 km/h) | 44.47 mph (71.57 km/h) |
| 50 mph (80.47 km/h) | 49.42 mph (79.53 km/h) |
| 55 mph (88.51 km/h) | 54.36 mph (87.48 km/h) |
| 60 mph (96.56 km/h) | 59.3 mph (95.43 km/h) |
| 65 mph (104.61 km/h) | 64.24 mph (103.39 km/h) |
| 70 mph (112.65 km/h) | 69.18 mph (111.34 km/h) |
| 75 mph (120.7 km/h) | 74.12 mph (119.29 km/h) |
| 80 mph (128.75 km/h) | 79.07 mph (127.24 km/h) |
| 85 mph (136.79 km/h) | 84.01 mph (135.2 km/h) |
| 90 mph (144.84 km/h) | 88.95 mph (143.15 km/h) |
| 95 mph (152.89 km/h) | 93.89 mph (151.1 km/h) |
| 100 mph (160.93 km/h) | 98.83 mph (159.06 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1771 | 2057 | 2215 | 2313 | 2419 | 2494 | 2577 | 2675 | 2811 | 2946 | 3097 | 3217 | 3436 | 3677 | 3866 | 3986 | 4054 | 4303 | 4649 | 5403 |
Better Fuel Economy Factory Ratios Increased Power
