just dumped out 5w20 mobil 1 full syn after 2700 miles because i get like that.. like black water...car is stock with a tune and it is not hammered except for the occasional 6100 rpm blast once a week
if i am lucky and only when fully warmed up.
will be doing the 5 w 30 thing from now on as i have dumped it in the past at 3500 miles (4.6 sohc) and wondered if i wasnt too premature as it looked not bad coming out
imho 5w20 is just too thin!!!