I was going to buy oil change for my 4.6 ltr. V6 and upon calling my local dealer to advise on the use of synthetic oil I was told that genuine GM and only genuine GM oil filters would do because of a check valve in them.

I find it hard to beleive that any of the major filter manufacturers have left this key piece out during production.

Is this true?

 

Thats why they call it the Stealership. I been using Royal Purple Synthetic Oil for bout 100k on my 5.3L and using Mobil filters. Aint had no problems. As long as you change it according to mileage or time, you will be fine. Dont go over like 10k miles every oil change as you may risk ring wear.