I have a 2014 with 77k miles. I drained the fluid and it looked like old oil but it didn't smell burned. I've never seen trans fluid that was brown. Is this normal for a Mazda? It was shifting fine except 1-2 could be a little rough sometimes. I don't believe in long life fluids so I change them early on all vehicles. I used 7 qts of Mobil 3309. Shifts perfectly now but the fluid was still dark when I set the level so I might do another change.