Into the weeds engine design for fuel efficiency discussion.

Personnally I am not a fan of the Pentaturd. Took one look when they first came out and I was a mechanic at a Dodge Jeep dealer, and decided I did not like it. Your results may differ, and that is OK. The old faithful 318/360 are readily available, so they are relatively inexpensive. Real easy to work on, while the Pentaturd with its DOHC and VVT can be a nightmare. The wiring would be a PITA.

I agree on the PITA on maintenance of the 3.6. I am approaching 75k and will be changing plugs soon. I will be checking the rockers as well while that far into it.