not sure what this means, but for what its worth..


i used castrol syntec for the first time this past oil change, ran it 4000 miles.. wasnt overly impressed, but when i switched back to mobil 1 this time, its only been 100 miles and the oil is already significantly darker than it normally is.. dunno what that means, but i may do a "quick change" if it continues to darken that fast again... my last oil change also used a K&N oil filter, back to mobil1 now