When to change oil?

[NorCal 4x4]

Originally Posted by cbgb

Maybe I missread some past posts but, I thought you needed to wait at least 10k miles before you switch to synthetic oil??

I have been looking at the AMSOIL website, [I'm not associated with Amsoil in any way], and they suggest using mineral based for 500 miles for break-in: "petroleum oil has a very low film strength which is ideal for breaking in a new engine. That is why we recommend you run the factory installed petroleum oil for about the first 500 miles".
My first change was with mineral based Castrol 5w 30 at 1200 miles. Since I'm mostly doing engine-easy, 45 mile trips, I want to wait until 3,500, (for synthetic), and I still have a free dealer oil and filter change I'll do at 2400.

BTW, I much prefer a dark dipstick with cross-hatching so you can see the level at a glance.

BTW2, Have any of you Mobil 1 guys looked at the Amsoil comparisons to Mobil 1? Their website is interesting. Any opinions?