Originally Posted by JoeyD

I think we can all agree that inferences can be made from the VQ35DE and HR about the 3.7. That being said I remember an article in a reputable magazine (don't remember which one it was a long time ago). The article tracked two 2004 350Zs they were both dynoed within 500 miles of new with comparable results. After 20K of driving and opposite break ins the one that was constantly beat up dynoed almost 20HP higher than the one that had been babied.

I can say that at 22K miles my 350 pulled harder then it did that day I got it. I subscribe to the theory that a 500 mile break in with varrying revs and only moderate acceleration is a good thing. But when 500 miles ticks over I check the oil for contamination and excess metal. If nothing is out of the ordinary my next drive we be like I stole it and so will every drive after that.