Now we are experiencing some luke warm weather the air con is being used a lot, but the trouble is even on 16 and flat out its still not cold enough to cool the car down.
They say you should regas every 2 years, however I have noticed on the Merc's in this hot weather you need to put on max for 10min for it to reach ice cold temp.
This only happening in stop start traffic or all the time? If in only stop start traffic maybe fans are not kicking in to draw air over the air con rad.
I am sure these have been tested in the UAE type places at 50 deg C +.
I had the same problem when i first got mine, but i worked out it was the children changing the temp up in the back which if you are in the front you have no idea about, it may not be this but once i changed that the problem went away?