This from a link on Edmunds... http://forums.stangnet.com/showthread.php?s=&threadid=181031 Question-- What are we looking at here? Obviously the Mobil 1 valve cover is clean, clean, clean. The other one run on the dreaded Castrol dino for 30K and then switched to the hated Castrol phony syn for 10 is much dirtier. When I look down into the oil fill hole on my Elantra run with cheap crap Wal-Mart dino, I see oil about the same color as is on my dip stick. After a little over 1000 miles it's between maple syrup and honey colored. Some is visible on the cams and rockers inside the engine. Things don't look as dirty as the dirty 'Stang. But they certainly don't look as clean as the Mobil 1 'Stang. It just looks like the oil does on my dipstick down there. Question-- If all the parts inside the engine look totally clean with no oil clinging to anything, is that necessarily a good thing? If you pulled out a dip stick and it looked as clean as the top of the good Mobil 1 valve cover would that be normal? It seems like there's a big difference between having some dirty oil clinging to some surfaces and the kind of "gelling" visible in those Toyota posts. How much dirt is too much dirt? Is perfect "you could eat off this surface" like the Mobil 1 picture overkill?