I may end up putting some in my Grand Marquis right before inspection.
It's got low compression on cylinder 5after being run with a bad injector. It's probably a ring issue. I'm not going to pull apart the engine to replace a set of rings and hone the cylinder.
If anything, I'll just change the engine. But if this can put enough soft metal in the rings to keep the compression up on cyinder 5 up enough that it doens't set the check engine light, money well spent.
Does it help the engine? No
Does it damage the engine? Potentially yes
Is it a net neutral? No