This adjustment merely serves as a driver preference to adjust against the temperature setting. My 4.8 has been set to coolest (blue bars) since delivery of car 7,500 miles and has had no impact on the poor airflow or failure to properly cool the cabin. The problems as noted on this board are fan speed, quanity of air and delivery points of the air from the front dash, particularly the failure to deliver air to the mid to lower areas on a consistent basis. I have seen this complaint posted on several boards all relating to the new e70. BMW has no response and unlike many of the other issues where tsbs have been issued, there has not been one yet on this issue.