I find the question intriguing. The more heat the A/C system has to absorb, the harder the system will theoretically work. Do the evaporator coils absorb more heat by passing cabin air through them more quickly or by allowing the air to move through more slowly? To me, that will be the key to the solution. Probably depends on the evaporator design, ie: the total surface area of the coil assembly, and on the volume of air the fan moves through it on a specific design. There may not be a single correct answer.
Either way, I doubt if the difference is measurable, but it is a good brain teaser.
Juanita @ auto-owner, everything else being equal, is it goo or bad for the compressor to have more or less on/off cycles?
Well, I always tend to assume that less on/off/on/off is easier on equipment, though I suppose it isn’t necessarily the case with every dang thing.
Currently I have the air set at high cool and low fan, and keep the fan low all the time and just adjust the cool to where it feels comfortable, but I do fiddle with it to keep the right balance. I do not like the noise or blast of air in my face with the reverse settings, but my inquiry was related to what is best combinations for the wear and tear on the compressor.
I share those opinions, and I had always thought that since I get colder as I dial the temperature control knob down (colder) with the fan at a constant speed (generally low) that I must be using more compressor to compensate for less circulating fan, if that makes sense.
Maybe it’s just more complicated than that.