Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 100/90-21 | 120/80-18 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 28.09 (713.4) | 25.56 (649.2) | -2.53 (-64.2) -9% |
| Width inches (mm) | 3.94 (100) | 4.72 (120) | 0.79 (20) 20% |
| Circum. inches (mm) | 88.24 (2241.21) | 80.3 (2039.52) | -7.94 (-201.69) -9% |
| Sidewall Height inches (mm) | 3.54 (90) | 3.78 (96) | 0.24 (6) 6.7% |
| Revolutions per mile (km) | 718.07 (446.19) | 789.08 (490.31) | 71.01 (44.12) 9.9% |
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 18.2 mph (29.29 km/h) |
| 25 mph (40.23 km/h) | 22.75 mph (36.61 km/h) |
| 30 mph (48.28 km/h) | 27.3 mph (43.94 km/h) |
| 35 mph (56.33 km/h) | 31.85 mph (51.26 km/h) |
| 40 mph (64.37 km/h) | 36.4 mph (58.58 km/h) |
| 45 mph (72.42 km/h) | 40.95 mph (65.9 km/h) |
| 50 mph (80.47 km/h) | 45.5 mph (73.23 km/h) |
| 55 mph (88.51 km/h) | 50.05 mph (80.55 km/h) |
| 60 mph (96.56 km/h) | 54.6 mph (87.87 km/h) |
| 65 mph (104.61 km/h) | 59.15 mph (95.19 km/h) |
| 70 mph (112.65 km/h) | 63.7 mph (102.52 km/h) |
| 75 mph (120.7 km/h) | 68.25 mph (109.84 km/h) |
| 80 mph (128.75 km/h) | 72.8 mph (117.16 km/h) |
| 85 mph (136.79 km/h) | 77.35 mph (124.48 km/h) |
| 90 mph (144.84 km/h) | 81.9 mph (131.81 km/h) |
| 95 mph (152.89 km/h) | 86.45 mph (139.13 km/h) |
| 100 mph (160.93 km/h) | 91 mph (146.45 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2008 | 2333 | 2512 | 2623 | 2743 | 2828 | 2922 | 3033 | 3187 | 3341 | 3512 | 3649 | 3896 | 4170 | 4384 | 4520 | 4597 | 4879 | 5272 | 6127 |
Better Fuel Economy Factory Ratios Increased Power
