I talked with Shell technical information today. I got a real, intelligent human who was very helpful. I asked about ZDDP in Rotella oil; he said that the formulation hasn't changed since 2006, and Rotella still has 1200 ppm of ZDDP and is fine for flat tappet cams. I also asked about oil filters and got a carefully-worded answer that essentially said "use Wix". As I try to do just that, this was a very good conversation. Just passing it along...
Thanks for the info, John. I just changed the oil with some Rotella in the beater yesterday, have always ran it with some ZDDP additive on top just to be safe.
Back in the '70's when I owned my Chevelle, I used Rotella T 10W30 oil in the engine, because that is the oil we used in the cars, truck, tractors & combine.
I use the Lucas Hot Rod & Classic brand myself, but noticed recently it was not recommended for cars with catalytic converters, so I've gone back to Rotella for the Estate Wagon.
T-5, T-6, doesn't matter? Asking for someone who's torn between preference for 5W cold pumpability over 40W high temp viscosity.
Why play chemist whats the matter with Mobil 1 or VR1 ? In walmart $23 on a sale day over 1300 ppm of zddp.If its good enough factory fill for Porsche Mercedes corvette its just fine for your buick.That what my all my 300-750HP cars get.
yes, there is good reason to be wary of interfering with the additive package present in various motor oils. More harm can be done than good according to my research. The particular balance of various ingredients is important. Disclaimer: I am not an engineer/technical expert. The comments from those that are seem sound to me however.
Mobil has been knocking down the ZDDP content in their oils. The 15W-50 still has the most of it, but nobody sells it around here these days. Costco barely stocks 30W any more. I use the RedLine to play it safe, and my 430 is still purring right along with it.
Flat tappets and high spring rates are the reason for adding more. A Porsche and LS engines have roller followers/lifters which have very little friction on the cam lobes. Just added insurance as I said, my stuff has a lot higher valve spring rate than anything factory produced. $10/oil change is a good investment on a 10k+ engine in my book.