When the A/C refrig pressure is displayed on the CC (item 7), on my E320, it reads in range 14-16 bar when car is at IDLE at say a stop light.

Then, when I pull off, the pressure drops to the 6-7 bar range.

Considering the engine and possibly the compressor are now running faster, why does the pressure drop? Just trying to understand what is happening.

Secondary question - On a new car, would there be a similar drop in pressure?

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Graham
85 300D,72 350SL, 98 E320, Outback 2.5