About the wax, did you see it feel it taste it? The wax story is a old tired one for sure. Most engine lubricating oils today are made from paraffinic crude oil. Paraffinic crude oil is recognized for its ability to resist thinning and thickening with temperature, as well as its lubricating properties and resistance to oxidation (sludge-forming tendencies). In the refining process, the paraffinic crude oil is broken down into many different products. One of the products is wax, and others are gasoline, kerosene, lubricating oils, asphalt, etc. Virtually every oil company uses paraffinic base stocks in blending its conventional engine oil products. Many people believe the term paraffinic to be synonymous with wax. Some have the misconception that paraffinic oils will coat the engine with a wax film that can result in engine deposits. This is not true. The confusion exists because paraffinic molecules can form wax crystals at low temperatures. In lubricating oils, this wax is removed in a refining process called de-waxing. Wax is a premium product obtained from crude oil, and to help produce the highest-quality base stocks available, Pennzoil uses base stocks with the minimum amount of wax possible. The end result is a motor oil product formulated with premium lubricating base oil. Then as for you maintenance schedule, it should be done to the manufacture specifications. As you can see your comments are incorrect. If you truly have sludge in your engine it is caused by other factors. Not changing often enough, engine design, dusty area using an incorrect filter, etc. Certainly not wax.