I've got some interesting, fresh first hand experience with the theory/practice of using thinner oil / thicker oil to cure ticking.

I switched to 5w30 for the last oil change (10w40 previously) and found the ticking actually increased a noticeable amount.

After a thousand miles or so, I added a thickening additive and immediately the ticking decreased substantially and has remained that way since.

Now I know this flies in the face of the logic that thinner oil will be better able to lubricate the top end but perhaps there's a correlation with the age and condition of my engine's oil passages. In my case, perhaps they need to be properly cleaned in order for thinner oil to work.

I'll try running a can of seafoam in the oil (it says you can use it) just before my next oil change to hopefully clean out the built up 'gunk'. Afterwards, I'll try using a thinner viscosity oil.

What do you all think? Pros? Cons?