E. E at the end or after the u. That changes the vowel.
Mad made, fad fade, nod node, bit bite, tot tote.
Th to me is like a double consonant, but I don’t even know if that is a rule about th or just something I have in my head. @Jeruba or @janbb might. Flutter, butter, mutter, to me the th affects a vowel the same way, but Luther is a good example where it doesn’t.
We used to spend time with the race car driver Rafael Matos and when he first started driving professionally the announcers called him May-toes. He couldn’t understand why it was so hard for the announcers. In English it makes sense. I told him if he spelled his name Mattos they would get it right. The double consonant changes the vowel in English.
Like I said, I could easily have been wrong about fluther, English is horrible for phonetic assumptions.