luvmy911

I'm getting about 15 in the city, 19 on the highway. Could be low because the of Super-Charger!

Not sure about ethanol in my gas though. I'm in Western PA.

wwest

Since the A/C system operates 24/7 then opening the A/C clutch circuit except when actual cooling, initial cabin cooldown, is needed will improve FE. My switch for that is conveniently mounted on the back wall of the console "cubby". It spends a LOT of time in the "off" position.

Macster

Monitoring engine load with the A/C on or off (barring having the A/C deal with a very hot cabin on a hot day) and at least with the autoclimate system which is what my cars have with its variable displacement A/C compressor the system barely causes an uptick on the percent of load when switched on and a down tick when switched off. These modern A/C systems are pretty darn efficient and do not present that much of a parasitic load.

Oh, what appears to be a goodly amount of parasitic load is the electrical power required to run the cabin vent fan and the head/tail lights.

Sincerely,

Macster.