There are always doubters who believe this and similar products would be completely unnecessary if not even dangerous for the engine. I've applied the LM-oil sludge flushing in some engines and can only say that I have noticed neither adverse effects nor can say that there is no effect would have been recorded. Older and driven in adverse conditions motors (frequent cold start with subsequent short-range, low-grade engine oil, defective engine management etc.) tend known to (basically a Teerderivat) recognize oil sludge, In my experience, the product eliminated when used properly this holds true to a large extent and so what it promises. That an oil sludge-free motor better and longer runs as a zugeschlammter, is probably obvious. In this respect, I find this product very useful. In any case, you should note that the product in the oil no longer than 200 kilometers should be driven, as otherwise damage can occur through possible oil film break on the engine !!