ok, so im about to run mobile1 10w30. Ive been reading these forums alot, and ive read a few times the mobile1 is a very thin 30wt, or a thick 20wt. Now, i have a series II 3800 engine, the n/a version, ad i was thinking, if i will be keeping the oil in my car for 6 months (which is about 5,000kms)should i dump in one litre of 15w40 or 30, whichever the race oil is to thicken up the oil a bit, or should i add a litre of amsoil 10w30, since i heard that oil thickens to a 40wt after a while?
need some suggestions here....im pretty confused.