Okay, just found this info which I found of interest and a great explanation of the adaptive feature....many of you may know this already, but I came over to this thread not knowing much...this was from another Challenger Forum:
"Just ensure you have good 93 octane in the tank...
Driver Adaptive's and related fuel table trim is probably the least understood algorithm contained within the NGC - Next Generation Controller (also called PCM)
There are long term fuel adaptive trim (100 start cycles) and short term fuel adaptive trim (50 start cycles). The NGC looks at what the fuel requirements to operate are during "closed loop" operations. The fuel trim algorithm is slowly and gradually attempting to bring the fuel consumption to best suit driving conditions and optimize the MPG by feedback from O2 and other sensors.
Short term and long term fuel trim are also used in analyzing KR (Knock Retard) and attempting to have the NGC (PCM) calibrate the engine timing based on quality of fuel. With different quality fuels and octane's, the NGC tries to always adjust for the best engine timing (advance/retard) to protect the engine from knock or prevent detonation. The knock sensors on the HEMI engine are quite sensitive and can be considered to be "engine microphones".
The PCM has the ability to do some rudimentary fuel tuning (all modern vehicles now do this) via "closed loop mode". It has two main modes of operation, closed loop and open loop. When the engine is started and heated up past 160 deg. F, the NGC (PCM) now goes into "closed loop" control whereby it takes feedback from sensors (ie. IAT, MAP, O2, Knock, etc.) and looks at the fuel efficiency and attempts to tweak out the current fuel tables to get the best MPG and engine efficiency.
Tromping the accelerator to the floor puts the PCM into OPEN loop where it now goes to fixed tables to do fuel mixture and o2 sensors are now bypassed.
So where does this wind up over time. Well, there is a number of "learn cycles" that The PCM goes into for fuel Adaptives, normal 100 start cycles, or a "quick learn" of 50 start cycles (using the headlight ON/OFF trick). During these times (cycles) fuel trim adaptive algorithms work on trying to get the best MPG. After the 100 cycles, the MPG magic is pretty much done until something is done to initial another "learn cycle" like clear memory.
These start cycles are a fixed "time-cycle" effort to build a fuel trim table and the algorithm will stop fuel trim after these 50 or 100 start cycles.
So if you have been driving around for a number of weeks, months in a laid back fashion, the PCM has learned this and attempted to get the best MPG for you and tuned down (slowly) performance. So, one day you tromp the gas hard or do some spirited driving and you notice the car "sluggish", or not quite as peppy as before. This could be the reason. Clearing out long term fuel table adaptive memory can sometimes help.
The PCM has a number of classes and types of internal memory. The fuel table Adaptive's are stored in volatile memory and when the fuse (F2) is pulled for at least 20-30 seconds, this memory is cleared and you can start over building a new set of Fuel Table Adaptive's for closed loop control (next 100 start cycles).
If you granny drive around town your car adapts to that type of driving. Then when you want to do a lot of quick aggressive driving the vehicle may seem sluggish and not "as responsive" as you remember. You may need to do something to the PCM called clearing driving fuel Adaptive's."
