So while watching car shows this morning I saw a commercial for a device called the
Oilyzer. I looked at the datasheet and website and it has me intrigued. There's no decent Google data on it yet, but I was curious if anyone on this forum has input on it. For the price I'm tempted to buy one and open it up to see if there's anything to it. Maybe it's just a CDS cell that calibrates to ambient light, then checks for how much light is blocked to determine good or bad. That would not really align with the "capacitive" description though.
If it uses the same method that some of the luxury cars use to determine oil life remaining, then this is probably a pretty good tool to have in the garage.
-Rod