Michael, you know what's kinda funny?
The K24 is also in Sue's 2006 TSX with almost 200K miles.
It has been on a steady diet of mostly Mobil1 5w30 and some 5w20 since new.
Filters have been WIX and M1; just started using a Fram.
I never check the oil. I do something like 6K OCIs.
Other than a water pump, alternator and PS pump, I have only done regular maintenance.
I did get the starter replaced and valves adjusted. (I am not recovered from surgery as yet).
The mechanic (one of the best in the South Bay) could not believe how clean it was under the valve cover.
I wonder what the difference is?