is it normal for the 3.0 4runner to have a loss of power when the a/c is on? my runner runs fine when the a/c is off but the moment i turn it on it feel like my car is hesitating/struggling to pick up speed.

 

When AC compressor clutch is on it's a drag on the engine, turning off AC make the clutch run free tiny bit to no drag so engine feel more power.

 

its common to lose power when your AC is on, thats why fuel economy takes a hit when its on.

that is also why you will notice on EFI rigs the AC is wired into the EFI with a sensor so that once it kicks on the idle will pick up so your rig doesn't die

 

Completely normal for almost ALL vehicles.
The ones with little HP to begin with notice the most lag.

 

An activated A/C can consume upwards of 30hp. Yep...you'll feel that.

 

You geared up? I feel the power loss only when going up like H3 or red hill, other then that I'm good.

 

yep, completely normal for all motors and vehicles, that's why i haven't never bothered fixing the ac in my yeehaw yet!

 

very normal, sometimes i turn it off to pass people :p

 

Definitely normal.

Wasn't there a Mythbusters episode about whether it was more fuel efficient to run with your windows down or with the A/C on?

IIRC, they said at city speeds it was more efficient to have your windows down, but on the highway, it was more efficient to have the A/C on...I could be wrong though.

Fink

 

fink- iirc, you're correct. i saw an article on the same topic with the same results

 

i've got a supplemental question on this topic:

i'm familiar with the additional load a compressor can add, which seems to "slow down" an engine.

but are there some additional vacuum (VAV) system parts, that if leaky could be contributing to his loss of power?

just wondering if there's anything else he should consider and check before dismissing his power loss as all due to the load of the compressor.

 

good point. might try the idle-up vac lines