Steve, you sound "Right On"
You sound "right on" with the description of the earlier cars. I get 40 degree vent temps on a 90 degree day which is fantastic but drop to about 52 or even 55 degrees at idle which is a bit annoying.
What was involved in the R-134 Conversion on the Benz? Standard o-ring, receiver drier and small part conversion or are there other things involved? I'm not too familiar with the MB.
I've done a few with good results but none match the cooling of the R-12 systems before. The 300CE is still R-12 but with the small condenser, I never even considered a 134 conversion for fear of worse cooling.
I did try an alternative refrigerant (ES-12a) with really good results almost identical to the R-12. 40 degree vent temps on a 90 degree day but almost 60 at idle which does not cut it.
Thanks for the info.