New drive belts decreased hp/torque...

[80sGuy]

I recently replaced the drive belts for the Alternator & PS/AC and had noticed a slight decrease in horsepower and torque - very slight though. The car drove tighter, but not as peppy as before. I also felt that it needed to rev a bit higher to get the power, especially when I accelerate just a tad as I do normally and it started to down-shift therefore resulted in higher rpm.
The belts are OEM from Mazda. There were no squeaks, squeals or anything similar after they were fitted in - just quiet like normal. The tensions were adjusted according to the feel of it - not too tight and not loose either (about 1/2 inch in play when push/pull the belts to check). When the A/C kicked in after a while, I can really feel the drag.
Is there a break-in period for this? Is it too tight or should I loosen it a bit? It isn't making any noise whatsoever, it just feels a bit different from and since the old belts.
I also had an oil change while I was at it, so the car should perform more than better. Also, I'd noticed some small oil leak dripping from the oil pan catch. I'll have to change the oil pan gaskets the next round. Not sure if this played a part in sluggishness.
Has anyone here ever experience this before?

[IukekiniProtege]

they very well could be too tight, which would have a negative affect on the power of the car seeing how more of the rotational force is being used to spin the belts, try loosening them, but not too much otherwise they will slip(you will hear it squeal)

[80sGuy]

I drove it around last night with the a/c on and see if the belts stretched. I checked the deflection rate this morning and it's about 1/2 inch or 1/4"-3/4" twist of the belt side to side. I have to drive it again to see the difference.
What a waste of gasoline!

[80sGuy]

I loosen both the belts today, just enough to where it won't squeak. It's amazing how I googled and NOTHING came up regarding this matter, all I got was "if you over tighten the belts, you'll bent the alternator bearings, etc".
But my car felt great again (xx fingers) and performed at its optimum without having being felt like it's dragging.
Thanx to 'IukekiniProtege' from this forum for suggesting the option.

Also, the only two other places that described similar experiences like this was from a Motorcycle and a Boat forum. The motorcycle guy had his belt over tighten and felt that his bike was shifting weird, after loosening it, he felt a great deal of pick up - or shifts better without having to rev the motor as much.
http://roadstarclinic.com/component/option,com_simpleboard/Itemid,91/func,view/catid,49/id,1019/
This was the same exact problem I had with my Protege after the belt installation.

I read that most mechanics prefer to have the belts tensioned a bit loose (just enough to where it won't squeal) than to having them being too tight. This prolongs the life of the belts as well as the Alternators and such.
Not only that, your vehicle will perform efficiently and in sync. Learn something new everyday!

[IukekiniProtege]

glad you got it figured out and nothing else was messed up, it took me a couple of try when i changed my belts to get them jsut tight enough to not squeal, thats how ive always done it on my cars, so im glad it helped