JLR likes to spec an ACEA C1 oil for use in our USA Td6's, but most dealers don't even carry a C1 oil. (Ask them which ACEA spec the bottle says, it's probably a C3 oil.) Fortunately, ACEA for 2021 is doing away with the C1 spec.

Ford (who built your Td6) says to run a CK-4 oil which is a 5w-40 if you encounter ANY biodiesel. Sure, the F-150 Power Stroke V6 diesel has a different SCR after-treatment system but it is otherwise the same long block. FCA did the same with their EcoDiesels in 2015 when they went from a 5w-30 oil spec to 5w-40, (which was to help protect the bearings.) Your motor, you decide. I suggest an ACEA C3 5w-40 like Motul's 8100 X-clean Gen2 5w-40. If you can find TRIAX EURO VX 5W-40 Full Synthetic, that looks like a good oil, as well.

https://www.acea.auto/publication/ac...equences-2021/