I currently have amsoil atf in my E and ive done two drain and fills with it. I like the wy it shifts much better than with z1 but when I drained the amsoil for the first drain and fill there was a lot more residue than normal on the magnant. I was going to do one more drain and fill with amsoil but if I drain it this time and there is a lot of debris on the magnant I might seitch brands. I'm not sure if it was dirtly just because it was cleaning out the stuff that z1 couldent or if it a sign of accelerated wear. If I see a lot this time then I guess it means accelerated wear. I was thinking about maybe switching to castrol import or back to z1. So has anyone ever used the castrol??