Tire Size Finder (optional):
Stock Sizes
- 255/75-16
Plus Sizes
- 255/75-16
Accepts P-Metric and Inches
| 285/40-15 | 285/40-18 | Difference | |
|---|---|---|---|
| Diameter inches (mm) | 23.98 (609) | 26.98 (685.2) | 3 (76.2) 12.5% |
| Width inches (mm) | 11.22 (285) | 11.22 (285) | 0 (0) 0% |
| Circum. inches (mm) | 75.32 (1913.23) | 84.75 (2152.62) | 9.42 (239.39) 12.5% |
| Sidewall Height inches (mm) | 4.49 (114) | 4.49 (114) | 0 (0) 0% |
| Revolutions per mile (km) | 841.17 (522.68) | 747.62 (464.55) | -93.54 (-58.13) -11.1% |
285/40-18 Tires
Speedometer Difference
| Speedo Reading | Actual Speed |
|---|---|
| 20 mph (32.19 km/h) | 22.5 mph (36.21 km/h) |
| 25 mph (40.23 km/h) | 28.13 mph (45.27 km/h) |
| 30 mph (48.28 km/h) | 33.75 mph (54.32 km/h) |
| 35 mph (56.33 km/h) | 39.38 mph (63.37 km/h) |
| 40 mph (64.37 km/h) | 45 mph (72.43 km/h) |
| 45 mph (72.42 km/h) | 50.63 mph (81.48 km/h) |
| 50 mph (80.47 km/h) | 56.26 mph (90.54 km/h) |
| 55 mph (88.51 km/h) | 61.88 mph (99.59 km/h) |
| 60 mph (96.56 km/h) | 67.51 mph (108.64 km/h) |
| 65 mph (104.61 km/h) | 73.13 mph (117.7 km/h) |
| 70 mph (112.65 km/h) | 78.76 mph (126.75 km/h) |
| 75 mph (120.7 km/h) | 84.38 mph (135.8 km/h) |
| 80 mph (128.75 km/h) | 90.01 mph (144.86 km/h) |
| 85 mph (136.79 km/h) | 95.64 mph (153.91 km/h) |
| 90 mph (144.84 km/h) | 101.26 mph (162.96 km/h) |
| 95 mph (152.89 km/h) | 106.89 mph (172.02 km/h) |
| 100 mph (160.93 km/h) | 112.51 mph (181.07 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1903 | 2210 | 2380 | 2485 | 2599 | 2680 | 2769 | 2874 | 3020 | 3166 | 3327 | 3457 | 3692 | 3951 | 4153 | 4283 | 4356 | 4623 | 4995 | 5805 |
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