Hmmm.

The cylinder is engine restore, compared to fuel system restore and upper cylinder lubricant. It is 95% naptha solvents, according to the MSDS. The rest is proprietary additives.

It is claimed by the manufacturer to seal microscopic leaks in the cylinder wall, thus improving compression. While the solvents would act as a cleaner, I don't see how the surface of the cylinder can get repaired by the use of this additive. And if it can somehow improve the surface finish, why would you need to continue to add a can with every oil change, wouldn't the fix be permanent?

What it primarily does, IMO, is dilute your quality synthetic motor oil with a low quality, unknown viscosity, mineral oil with unknown additives. Those additives may or may not play nicely with the additives in your synthetic motor oil.

It is also available in different 'formulas' for 4, 6, or 8 cylinder engines. I wonder how the different additives know how many cylinders there are?

Colour me skeptical. I would put this solidly in the snake oil category. Specifically recommended against by BMW, and personally I wouldn't put it in any engine that I cared about. But if you like it, and use it, please make sure to check engine compression before and after so you can report the difference.

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Retired:
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