Quote Originally Posted by Saturatedpsi View Post
I've yet to see any automobile advertising give any efficiency rating on the air conditioners...if they were overly concerned with compressor run times, they wouldn't build cars with black interiors.

So far as pressures, I'm just guessing they'd rather design around 200 psi, rather than 350 (R-22) or 550 (R-410A).
I have not seen any car companies give efficiency ratings on the AC system either, but I think it would be very hard to determine the efficiency of an auto AC system because of a lot of factors not present when rating the efficiency of a home AC. For example, engine, and therefore compressor RPM varies significantly while driving, and airflow over the condenser varies greatly with speed. The efficiency of the system on car x may comparatively be very good at idle sitting still but not good on the highway compared to the system in car y. I actually do think that they are concerned with compressor on time because if I remember correctly, feel free to correct me if I am wrong, the highway fuel economy test cycle is performed at 55 MPH WITH THE AC ON MAX. The more time the compressor is on, the worse the gas mileage rating will be. I have no idea why they build cars with black interiors. I guess that is what people want? But on the fuel economy test cycle, they could probably use any interior color they want for the test vehicle anyway, but I could be wrong.