I only use fully synthetic in my lexus. If you are going to ask for the highest quality oil you better buy it elsewhere and just have to dealer do the oil change. From my experience the dealer charges twice as much for the oil as you can buy it a local parts store. There are many options available but all the studies i have read show that royal purle and Redline oil are the best, also remember even though it is synthetic oil and it takes longer to break down its not a bad idea to change your oil early. Personally i change mine every 3,000 miles, i figure if i spent 45,000 on a car i might as well maintain it really well!
What kind of oil do u use though? And also, is Eneos oil any good, which brand is best? I heard a lot of people using mobil 1 syn, and also do u know wat kind of oil the lexus dealership uses?
I use redline oil in my lexus, i have no burning problems and it runs great. Redline oil does cost more per quart though.
Some people might consider the oil i use and how often i change my oil it over kill but it does no damage and can only help the engine.