Ford (and Jaguar - previously owned by Ford) used the same transmission and specified their own branded product, Mercon SP. While Ford and ZF won't state it, it's widely believed the Mercon SP is LG6. Mercon SP is usually available at a lower cost and is what I'm running in my transmission. A Google search will reveal a lot of discussion on this.
Interestingly, Ford tried to supersede SP with their more universal Mercon LV. Apparently, they began having failures in the ZF transmissions and were forced to bring back SP and reverse their recommendation of superseding with LV. That made me a little leery of trying a universal fluid like MaxLife, Liquimoly, etc.
AM.