A while ago I mentioned a friend who had his 2.8 V6 12v Audi engine rebuilt. In this context I was talking about the "collapsed rings" which still did not became obvious in a compression test. Compression was still well within factory specs, but oil consumption was excessive. Some of you accused him of having beaten the snot out of his car. I asked my friend to elaborate on the "collapsed rings," and this is what he told me: "The middle ring of our three piece oil retention rings is just a "squiggle" that sine waves up and down and holds the upper and lower rings in place. The three pieces form a matrix that, like a broom, sweeps the oil off the cylinder walls. My oil rings had a "pancaked" middle ring that severely diminished the available sweeping area of the matrix." Can anybody tell me if this is a typical ring setup, and how such a setup is affected by carbon buildup when compared to other ring setups? For what it's worth, this engine has low tension rings, and my friend had them replaced with gapless, normal tension rings. This took quite some machining, from what I heard.