Does anyone else notice a significant loss of acceleration power when the AC is on?

Not really. It's funny you ask, I was trying the other day while accelerating to turn the AC on and off and I haven't really noticed much difference. With the Civic that I had there was a little bit of a difference, but it doesn't take much to slow down a sewing machine engine.

Most of my previous cars turning off the AC was like hitting a boost button. I don't notice the AC in the Xterra at all.

Hmmm, I wonder if there is something else that might be related?

I feel a definate loss of power when the AC is on...But it was like that in my Blazer and in my Saturn as well...so I'm kinda used to it...

I can feel a difference when the AC is on, you are not alone.

Yes i have noticed the same thing, especially when excelerating. Then i turn off the Ac and boom more power.

definitely.

Yeah, there's definetly a loss in power. When I had my old car (a '91 Camry) it was like driving two different cars. With the X, I notice it, but it's not that big of a deal.

consumes more gas with the AC on, so some loss of power can be expected... notwithstanding there is still enough power left for good acceleration.

Okay since no one has given a technical answer.....

Turning on the AC uses an accessory that is belt driven. Sinc ethe Xterra has many belts and not a serpentine belt it can create different amounts of friction on your engine.

Think of the performance gained by using an electric fan rather than the belt-driven clutch fan. When your AC is off it has less friction and less rotating mass, when its engaged, you hav emore drag on the engine, not to mention the engine is trying to push it too.

Not all cars are as dramatic, but usually lower power vehicle feel a greater effect.

Definitely some power loss.

I sure do. Isn't that in all cars? That's why i hardly use my AC. Plus, it waste gas. Go natural and roll down the windows!! LOL