Tire Calibration and Pressure Sensing
First port of call for any would-be off-roader is a swap to an appropriate set of wheels and tires. Since this usually involves a change to the rolling circumference, the speedometer needs to be recalibrated to take account of the larger rubber.
Tuning devices from Edge Products and Superchips simplify the recalibration to a larger tire size. With the app-based Flashcal+, for instance, the Tire Size Wizard uses the phone’s built-in GPS to determine your actual speed and the disparity between that figure and the speedometer reading. It’s a highly accurate solution that automatically takes any difference between the tire’s marked size and true size into account.
Adjustments to the OE tire pressure monitoring system (TPMS) are the next logical step. “Owners may prefer to retain their factory TPMS sensors,” says White. “We give them the ability to suppress them so they can set the pressure lower. A Jeep Wrangler throws a warning light if you go below 22 psi. We can’t reprogram the system to a lower pressure threshold, but we can disable the TPMS sensors altogether so that when the owner goes rock crawling and is running at 9 psi air pressure, they don’t get the light. When they’re done and they put the air back in for the drive home, they can re-enable the system.”
For Jeep Wranglers and Gladiators, products offering tire-size recalibration and TPMS disablement include the Superchips Flashcal+, an entry-level handheld tuner, and the top-of-the-line TrailDash 3 – an on-dash display that’s loaded with performance programming. For Ford Broncos, the Flashcal is a great-value programmer that enables tire diameter changes and TPMS override.
Products like the Flashcal+ or the Edge EZX, an inline tuner for diesel pickups, give you the ability to adjust settings on the fly without having to reflash the ECM. You can disable TPMS when you get to the trailhead and re-enable it when you get back on the highway.
Shop tuners from Edge and Superchips now