Originally Posted by miltonlin

You hit the nail on the head
It is insurance and peace of mind for me. Toyota/Lexus oweners have had their 1MZFE engines sludge, even when they claimed to change the oil regularly. Neglect or design flaw? The design flaw to me is the location of the oil filter - perfect spot to burn yourself on the exhaust manifold and a leaky mess.

Not really important to me, but it is an indication that this car MAY need something more than what Dino provides. I had started using M1 synthetic before all the sludge stories came out anyway.

I'll stick with M1 for the life of the car until someone says otherwise. I tried to keep the same M1 super synthetic everytime, but then M1 changed their formula too The manual stating oil change and transmission fluid change intervals just was worthless.

Originally Posted by code58

I have been baffled from the beginning on the sludge and the tranny problems on the RX. Some have sludge (and tranny problems) with meticulous care and some don't have problems with mediocre care. She has 123k on the 99RX now and it has had mediocre care until the last year and has had no tranny prob's and no sludge with dino and different brands of oil and Fram filters. Frankly don't know what to say.