Interesting topic and replies. I do have some concerns after reading these posts (dual filtration testing starts toward the bottom):
http://theoildrop.server101.com/ubb/...6;t=000513;p=4
and opinions that adding a bypass filter may void your warranty.
A quote from BobTheOilGuy:
"A bypass filtration system is a design/ engineering change, not a direct replacement of the oem system. therefore the moss act would not apply and warr can be denied no matter what. I have seen toyota tell people that they must pull of the aftermarket bypass system if they want to maintain their warr. " "My advise, get it in writing so that approval is documented." And one more quote: "Ultimatly it's up to each dealer on warr approval but as pointed out, a mechanic might allow it,or a service writer, but, when it comes to higher ups getting involved, a great many car companies look for ways out and without written approval for such, you may or may not get it depending on your relationship with that dealer."
http://theoildrop.server101.com/ubb/...c;f=6;t=000898
Personally, ~$20 for an UOA is about the cost of 5 quarts of Mobil 1 and I would tend to opt for changing the oil and filter and request an UOA if I suspected an engine problem (coolent getting in the oil for example) or wanted a periodic analysis to keep a history. If I owned a big rig diesel that the fill is in gallons of oil, then UOA's would be a cheaper alternative. But to each their own and do what works for you.