The Ultimate Forscan Guide: Speedometer Calibration for Larger Tires

Electronic Calibration: The Modern Alternative to Gear Swaps

If you own a Ford truck made after 2011, you have a powerful tool at your fingertips. By using a software called **Forscan** and a simple OBDII adapter, you can tell your truck's computer the exact circumference of your new tires, restoring accuracy to your speedometer and shift points.

Required Hardware: The ELM327 Adapter

You need a bridge between your laptop and your truck's OBDII port. We highly recommend a high-quality wired adapter like the **OBDLink EX**. These provide the stability required for safely modifying the truck's core software.

Step-by-Step Calibration

1. Backup Your Data: Save a copy of your original "As-Built" BCM data.
2. Calculate Circumference: Calculate your tire's actual circumference in millimeters.
3. Modify BCM: Enter the new millimeter value into the BCM configuration.
4. Relearn: Perform a PCM Module Initialization to sync the new data.

Conclusion: The Professional Edge

Correcting your speedometer maintains the health of your transmission and keeps your odometer accurate. Use our Speedometer and Circumference Calc to get the exact data you need for Forscan.