Under which driving conditions can I use the overdrive in the new Unlimited Jeep?
I have an automatic system. Is the oberdrive could when I drive on the
road or only in off road conditions?

Hello Roli-ga,

Congratulations on the new jeep!

I have some information for you on when you should drive with
overdrive on. In addition, I am going to recommend looking in your
owners' manual for information as well.

How to use overdrive

 Overdrive keeps your car at a lower RPM at higher speeds to help
increase fuel efficiency.  When it is switched on, the transmission
shifts into overdrive after the certain speed is reached (usually 30 -
40 mph depending on the load)

Sometimes, driving uphill or towing a trailer, the transmission cannot
decide to stay in overdrive and shifts itself to a lower gear and then
it usually starts to shift back and forth. If that situation happens,
it is recommended to switch your overdrive off. You may need to switch
it off if you drive in a mountainous or hilly area.

You also may need to switch it off when you want to slow down using
the engine braking, for example, driving downhill.
http://www.samarins.com/maintenance/transmain.html


If this answer requires further explanation, please request
clarification before rating it, and I'll be happy to look into this
further.
Nenna-GA
Google Answers Researcher

It doesn't matter.  Let the automatic transmission decide. Overdrive
will increase your gas mileage.  The only time I turn my off is going
up a hill and the transmission is shifting up and down and up and down
between overdrive and drive.

You're not going to hurt anything.