Originally Posted by compu_85

Does your car have a belt driven fan? If so the fan is spinning much faster when moving. Plus you get the airflow over the condenser from the wind. Both of those lower its temp, which lowers the high side pressure.

I'll have to look at that reading in my Passat. It has twin electric fans so their speed isn't dependent on engine speed, and they're very powerful to cool the engine bay during a 1100*F DPF regen.

-J