Here's my 2 cents, I thought I'd check my a/c temp after reading this thread. Best it would do was 50deg with outside air at 90. I tweaked the freon level some and got it down to 42. Normally an a/c should cool about 20 to 25 deg below outside air. OEM states 1.12 lbs. I put in about 1.25lbs. Any auto will cool less at idle since the a/c compressor is turning slower thus moving less refrigerant. Watching the a/c gauges optimum pressure is around 900 rpm's when not moving. Oh and yes on recirc mode it will cool better since your recooling the inside air. Granted a/c theory says your removing the heat from the air not cooling it. Ok well there's my thoughts 
