Power Loss with A/C On

ChevyHDGert · May 21, 2004

How much power loss is typical with the A/C on?

I've got the 6.0L and the power loss is very noticeable. I know I should expect some but I'm just wondering how much is too much?

citydriver · May 21, 2004

Join the club..I know I only have a '95 w/a 5.7L but it gets down right DOGGY off of the line when the A/C is on...I think between the compressor and the alternater,it ROBS almost 20 horses,at least thats what it feels like

SteveCZ · May 21, 2004

Same here..... gotta really wind her up to get her goin with the A/C on

One good thing about the A/C is its meat locker cold though!!!

OUMike · May 21, 2004

Hmm....granted I have a 94' 4.3L, I don't really notice any power loss. My mileage is a little different, but not much. My AC usually effects mileage by about .5-.9 mpg. Maybe my truck is just extra efficient??

asepgrad98 · May 21, 2004

i have been told about 10hp

GONZO · May 21, 2004

you have a 6.0L and can tell a differance in power when the ac is on?!

i would say something is wrong, my 6.0L doesn't change a bit power wise when ac is on. it will use slightly more gas when ac is on... maybe .5 mpg. my truck pulls right at the gcvwr with ac on... still has plenty of power.

the only cars i've "noticed" when the ac was on is usually 4cyl cars that are already under powered to beging with.

robsawatsky · May 22, 2004

I've got a 5.7 in my 2000 pickup and I can hear (sometimes) when the compressor comes on but haven't noticed any power difference. Very unlike the 97 Plymouth Grand Voyager with 3.0 that loses considerable acceleration with the AC on.

Xao · May 23, 2004

I have to say that I have not noticed any power loss with my '04 with a 5.3.

I hear the compressor turn on and I can vouch like the others that the gas mileage takes a small hit.

Now, I haven't towed a load with the air yet, so maybe that makes a difference...

JamesB · May 24, 2004

With my '02 Z71 5.3 w/ 3.73s, I don't even notice a difference with the A/C on. Towing or not... However, My '91 Suburban with a 350 was a dog with the A/C on...

James.

Wingnut · May 24, 2004

Neither of mine have hardly any power loss with the AC.

I won't lie and say that there isn't one, it just isn't all that noticeable.

5.3 in the 02.

5.7 in 92.

Supurban · June 2, 2004

In my 04 5.3L Sub it is barely noticable that the AC is running. An easy way to exaggerate the lag is to turn on the compressor as you are accelerating up a highway ramp. While I haven't towed with this vehicle, I would turn off the AC anyway on hills and the like. On hot, hard tows, I actually used to run my heater (as an auxilliary radiator) with the windows down while towing two Sea-Doos behind my 2.2L Subaru Legacy just to be sure!

JBZ71 · June 2, 2004

No loss here either...(5.3) Wonder what gives????

az'03Silverado · June 2, 2004

Come on down to AZ in the summer when it's a good 110+. I have the A/C on plus every time I stop the cooling fan clutch kicks in. Feels downright gutless. Sounds cool though sucking all of that air through the radiator.

99Silver6.0 · June 2, 2004

Torque managment pulls some timing when the A/C is on. Thats part of the reason it runs kind of crummy.

Import Hater · June 3, 2004

Well....technically, no power is lost. If you try to measure max power on a dyno or your nearest on ramp, you'd be at wide open throttle right? As far as I know, modern vehicles have a logic in their PCMs to disengage the A/C clutch at WOT to make sure the A/C doesn't steal any power.

Just cruising along though, the drain varies based on A/C system pressure/oil levels, compressor efficiency, and ambient temp. I wouldn't be surprised if it's as high as 20hp on some vehicles. I remember a funny bit of creative writing in one of the car mags a while back referring to driving a puny little 4 banger econobox. "Turning off the A/C was like turning on a supercharger."

Rob