Quote Originally Posted by joeybsyc
My question is this though... even though the GM EOS has alot of zinc in it, aren't these all measured in PPM, meaning if you took the same amount of each and measured the zinc within, that's what you have? If this is correct, then you also gotta factor in how many ounces of the stuff in question is going in your engine... if you're looking at oil, you can times that number by 5 quarts, 6 in some cases.... but you only put one little bottle of the EOS in. I think even a bottle of STP is quite a bit bigger than the EOS bottle is it not? (how many oz. is actually in a bottle of it?) Personally, I use Shell Rotella or Delo400 diesel oil in 15w40, as I have read good things about both, and even with the new lower content of zinc, they still have more than most regular oils. I also use STP, red bottle if i find it, if not blue won't hurt either, and adds another 2436ppm of zinc. My grandfather swore by it, and used in in every oil change for 60 years and it never hurt anything, so I don't think its gonna do me any harm either.
It may not hurt anything but there are products out there that are much better.