In hopes of getting in front of another endless oil debate. Forget what Mobil says; forget you ever heard of the semi-mythical MS-10725; and forget the Owner's Manual reference to API standard CF as both of the latter are at least a decade out of date. All you need to know is 1) use full synthetic oil; 2) 0W-40 or 5W-40 are both fine although I suspect most folks use 5W-40; and 3) see http://www.api.org/products-and-service ... categories for the proper API rating which MUST be stamped on whatever you buy (CI-4, CJ-4, or CK-4 are all fine - S and F ratings are not fine unless they also have on of the listed C ratings).

A common choice is Shell Rotella T-6 5W-40 which is now CK-4 rated although some that's rated CJ-4 may still be on the shelf. There are other options that meet the listed criteria.