this can be a good question for mythbusters so I want to post it there. Small cars with small engines has a considerable drop in MPG when turning the A/C on but, what happens with our big mopars with big engines?

Sometimes I had readed that the mpg drop when turning the A/C ON in this cars is insignificant.

So what do the experts think?

 

Same effect no matter the size of engine/car. A/C systems use compressors and these take considerable energy to operate. You don't feel it as much in a larger engined vehicle because of the greater torque and horsepower to spare compared to a economy car.

 

Hybrid has electric Compressor... No HP loss or gain

 

True, but it's going to still reduce the range as much as a conventional vehicle. There are no free lunches.

 

I'm Glad to see there are 2 smart azz in the house..

 

Aww, Hell, I thought you were serious. Now I feel silly.

 

but, how cares about hybrid cars jejeje

well so definitely A/C ON equals to less MPG and less power, no care engine size

 

With my 440 Imperial, I see no difference in gas mileage. If anything, may be a small improvement. It heats up the engine compartment more, reducing a bit pumping loss, and it also may get the engine a bit warmer, and this a bit more (part load) efficient. (do not confuse volumetric efficiency loss at higher under-hood temps with thermal efficiency due less heat loss to the walls and to less drag in the bearings)

 

Yeah, I guess there's no rule set in stone. My E-350 work truck gets 9-10 MPG with or without the air on (or how heavy it's loaded, towing, highway or town, etc.)

 

When my A/C compressor was working and after the engine rebuild I didn't notice a MPG change but I always noticed more heat just near the brake pedal not sure if it's just my imagination or if I was measuring incorrectly my MPG.

I need to take a time to fix my A/C to take again an MPG test with the A/C always on

 

ya but the old V2 compreser shook like an Milwaukee shaker. I.E. HD