Here's how it works:
* Overdrive Engaged (Button OFF/Not Illuminated): The transmission uses all available gears, including the highest (overdrive) gear. This is generally the most fuel-efficient setting for highway driving.
* Overdrive Disengaged (Button ON/Illuminated): The transmission will shift through the lower gears, but will not use overdrive. This is useful for:
* Towing or hauling heavy loads: Disengaging overdrive prevents the transmission from hunting between gears and keeps the engine in a higher RPM range for better power.
* Steep inclines: Similar to towing, keeping the engine in a lower gear provides more power for climbing hills.
* Passing: Provides quicker acceleration for passing slower vehicles.
Essentially, the button acts as a manual override to limit the transmission's top gear, forcing it to stay in a lower, more powerful gear. When you're done needing the extra power, you simply press the button again to re-engage overdrive.
