Well, my temps are from last year as my AC is nonfunctional right now. (I poked a hole in my parallel flow condenser when taking the engine out last fall.) I have a new condenser coming in today and may be back up and running this weekend.

I had a parallel flow condenser. I first ran it on r134a. My vent temps with the blower on high were mid 40sF. At a stoplight they rose to ~60F. I wasn't pleased with that so I decided to take out the r134a and put r12 in. I noticed a slight increase in performance with just a few degrees cooler a both idle and on the highway. If I put the blower on low vs high I noticed a substantial decrease in vent temp. About 5F.

The condenser I just ordered is much bigger. The one I had originally was 24.5 x 14. The new one is 26 x 16. I did a bunch of measurements and shuffling my old condenser around and I should be able to make it fit. We'll see how much of a difference this makes. I will be putting r12 back in since I now have a recharge and recycle machine in my garage.

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2009 ML320 Bluetec
1985 300CD
1981 300TD

Past Mercedes
1979 300TD
1982 300TD
2000 E320 4Matic Wagon
1998 E430
1984 300SD
1980 300SD