Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 120/85-18 | 29.5/8.5-17.5 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 26.03 (661.2) | 29.58 (751.22) | 3.54 (90.02) 13.6% |
| Width inches (mm) | 4.72 (120) | 8.5 (216) | 3.78 (96) 80% |
| Circum. inches (mm) | 81.78 (2077.22) | 92.91 (2360.03) | 11.13 (282.81) 13.6% |
| Sidewall Height inches (mm) | 4.02 (102) | 6.04 (153.36) | 2.02 (51.36) 50.4% |
| Revolutions per mile (km) | 774.76 (481.41) | 681.92 (423.72) | -92.84 (-57.69) -12% |
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 22.72 mph (36.57 km/h) |
| 25 mph (40.23 km/h) | 28.4 mph (45.71 km/h) |
| 30 mph (48.28 km/h) | 34.08 mph (54.85 km/h) |
| 35 mph (56.33 km/h) | 39.77 mph (64 km/h) |
| 40 mph (64.37 km/h) | 45.45 mph (73.14 km/h) |
| 45 mph (72.42 km/h) | 51.13 mph (82.28 km/h) |
| 50 mph (80.47 km/h) | 56.81 mph (91.42 km/h) |
| 55 mph (88.51 km/h) | 62.49 mph (100.56 km/h) |
| 60 mph (96.56 km/h) | 68.17 mph (109.71 km/h) |
| 65 mph (104.61 km/h) | 73.85 mph (118.85 km/h) |
| 70 mph (112.65 km/h) | 79.53 mph (127.99 km/h) |
| 75 mph (120.7 km/h) | 85.21 mph (137.13 km/h) |
| 80 mph (128.75 km/h) | 90.89 mph (146.28 km/h) |
| 85 mph (136.79 km/h) | 96.57 mph (155.42 km/h) |
| 90 mph (144.84 km/h) | 102.25 mph (164.56 km/h) |
| 95 mph (152.89 km/h) | 107.93 mph (173.7 km/h) |
| 100 mph (160.93 km/h) | 113.61 mph (182.85 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1735 | 2016 | 2171 | 2267 | 2370 | 2444 | 2525 | 2621 | 2754 | 2887 | 3035 | 3153 | 3367 | 3604 | 3788 | 3906 | 3973 | 4217 | 4556 | 5295 |
Better Fuel Economy Factory Ratios Increased Power
