When the air conditioner is running its performance drops substantially. Often during low revs, it lurches and at higher speeds I can feel it missing. The problem is that it does not happened consistently, but often enough that I have had comments from passengers and my son and husband have both mentioned it when they drove the car. I have complained to the dealer, but when they take it out it behaves OK and they can't fix a problem they can't feel. At one point, it was lurching and then the engine light would come on. I figured the dealer would have no problems determining what the problem is then, but the computer reported a starter problem so they could not determine what the problem was. They reset the engine light a few times before they decided to follow the wiring thorough the module where the starter is and found a lose wire in the daytime lights They fixed that and I haven't had the engine light come on again. However, I still have the problem of lesser performance with the air conditioning running. This is my only complaint with the car. I am still hoping it can be fixed.
I had my new car choice down to 2. The 2002 Subaru Outback Sport won due to its looks and the All Wheel Drive. It handles wonderfully and is the perfect size for my dog. I like that I can put her in the back without putting the seats down. The car has great pick-up and good mileage. I really enjoyed the heated seats during the winter months.
With regards to the air conditioning affecting performance. Worry not, this is normal as the compressor is driven by the engine. Alas everything comes at a price.
A/C units in cars take their power from the engine, if you have ever lived in the SouthEast, you just don't think about it, but I guess you must live where it is cold, You won't notice the performance loss if you have a bigger engine, V6 or higher, at that point, there is plenty of power to go around.