Yes, the 6.4 recommended oil is 0W40 and they suggest you use Pennzoil Ultra Platinum ... It is expensive. I use Mobile 1 0W40 in my 6.4 and the NAPA gold filter ...the filter is considerably smaller than those on the 5.7s
They still recommend Material Standard MS-6395, I believe Pennziol Ultra Platinum is one of a few that claims to meet the standard. On the other hand I think the 6395 standard to be pretty old (maybe explains why so few certify it?) so be sure to meet or exceed the specified API standard.
Robert
