I knew in advance that using this additive would not be a permanent solution to the oil blow-by problem with my car. But it turned out to cause an even bigger problem that left me very disappointed. Within 15 minutes of pouring it into my engine it triggered the "check engine" dashboard warning light. I used it prior to leaving on a two-hour road trip and I kept hoping that this was nothing more than a temporary adjustment; but nothing changed after that. The check engine light stayed on permanently; so I quit using it after the third bottle. It was burning off just as quickly as high mileage oils so I went back to using them, instead, and will eventually have my engine overhauled. The CEL was not even on before using this additive for the first time! This so-called "Ring Seal/Smoke Repair" oil additive is not recommended; it does more harm than good. I suspect that it is too thick for the passages through which the engine oil flows. This could be harmful to an engine due to the lack of effective cooling and lubricating properties.