Let me agree and elaborate on m(a)ace's post. I know this is an old post, but for the sake of those doing a search, here goes. I learned most of this less than a month after my used purchase and 15-20 minutes after hitting the beach. I have an 09 JKU automatic, so some of this wont apply to manuals. After much research it seems the general consensus for beach driving is to air down to 15-20 psi as a starting point. I would say the posts above agree with that. Use 4L. '07-'11 auto's will overheat in 4H unless travelling 25-30 mph. Related to that, get an auxillary transmission cooler. The stock cooler is mounted to the a/c condenser and is tucked behind a cross-member and the front bumper. It is undersized and gets almost zero airflow. You can also turn your a/c on to force the cooling fan to come on. I believe 4L automatically turns ESP off, so that's covered. Also, turn O/D off. More than a little late to help the original question, but hopefully useful info to others. You can find more related info by searching this and other forums for "hot oil".

 

I employed some of the techniques in this thread over the weekend. Reading this before I went wheeling this weekend made me a better driver.

 

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the wrangler speedo still caps out at 100, stick or auto, same 100 hehe, it comes down to who takes more parts off to lose the weight to hit that 100 first with a jeep drag!