MB Enthusiast

2008 S550

What should be the expect air conditioning temp coming out of Middle vent when on low

I am seeing 50 - 55

I thought 40 is normal - am I incorrect

alx

It is a variable compressor system. Put on max cool, keep rpms at 1500 rpms and measure after 60 seconds. Anything around 50 degrees discharge temp is ok. Ideally you want to hook up gauges on the low side and see what you get.

Is the ac performance satisfactory? If it is- leave it alone.

MB Enthusiast

AC seems ok but not great

I put thermometer in vent ran on low and drove 20 minutes - 50 the lowest most of the time 55