Here's why:
* Off-roading: In off-road situations, you'll often need lower gears for more torque and control. Overdrive is typically bypassed in these situations. In fact, many Jeeps utilize a "low range" transfer case which significantly reduces the gear ratio, overriding any overdrive.
* Towing: When towing heavy loads, you'll likely need more power and torque, negating the benefits of overdrive.
* Hill climbing: Steep inclines often require lower gears to maintain sufficient speed and prevent engine strain.
* Engine braking: In some cases, lower gears are needed for engine braking down steep grades, which overdrive would prevent.
Overdrive is a convenience feature primarily for highway driving and fuel efficiency. Whether you use it in your Jeep Wrangler will depend entirely on the driving conditions. It's perfectly acceptable, and often necessary, to drive without using overdrive.
