I've been reading lots of threads here on the topic of transmission fluid changes. I am really confused by all of this as I the manual says change the fluid at 6 years or 100k miles yet most threads suggest that you do it earlier. I've got an '03 4cyl auto.

I have become a strong believer in "if it a'int broke don't fix it" mainly because often when I take a car in for service, something gets screwed up.

So I do only what the manual says and I do it myself.

As for the transmission fluid, mine is still very pink, clean and smells fine. The car shifts perfectly.

Do I really need to change this at 6 years?

Thanks.