snake oil if you ask me, the saturn 1.9 is renowned for burning oil due to deposits in the oil control ring lands, and geniuses saying "oh it's burning oil let's buy the cheapest conventional for top-up and never change it" really exacerbates the problem. the only truly effective way i've found to clean them out is to disassemble the engine and scrape the carbon out with a pick, i've tried a number of soaks and oil additives and never saw anywhere near the reduction in oil consumption that i did from disassembly and manual cleaning.
don't get me wrong, i have seen some improvement by running 15w40 hdeo and going on a few hundred miles of nice spriited drives, but it still wasn't close to the level of improvement that actually scraping that carbon out of the ring lands with the engine apart achieved.