back when HTPerformance was around they put amsoil euro 10w40 in my tranny. that worked ok for a couple years. But i had a 3rd gear grind.
I then changed that fluid out to penzoil syncromesh , 3rd gear grind is gone and its been in for about 2 years i think with no issues.
When i change it out again , im gunna suck it up and buy the ford stuff.
6 Duratec Focus
3 04 zx4's
2 05 zx3's
1 03 zx3