Originally Posted by kluken

I doubt Toyota is putting Synthetic in at the factory. There may be some additives to the factory oil to help the initila break in, but leaving it in 5k is just your GM pulling it out of his ***. I have no conclusive evidence to back this up, other than years of expierience and reading other research and reviews... I liek to get the factory oil out fairly quickly as the initila few hundred miles is when the engine is going through its inital break in, more wear and seating going on, extra friction, etc. I used to pull factory oil at 1K and let dealer do that first change (as with many of my cars the first oil change was free) then at 2K i woudl pull that and go to synthetic. Yes it is overkill and a bit anl, but I figur eI am flushing out any crap that accumulated duringt he worst part of break in and provided the engine fresh oil during this period. At 2K I gfo synthetic and used to chaneg it every 3k miles. With my TL I began to use the maintenace compute rin the car and would change the oil when it said oil life was 30%. That was usually 5500 miles. In the TCH I kept factory oil until 1600 then switched to Mobil1 0W20 and will probably change the oil every 4k or 5k miles.