transmission on 2005 Chevrolet Malibu Maxx

how often should fluid be changed

Asked by for the 2005 Chevrolet Malibu Maxx
Usually I change my transmission fluid every 30,000
1 more answer
the manual says every 50000 miles, but then has a footnote that says it never needs to be changed unless you drive in mountainous terrain, tow, commute regularly in temperatures around 90 degrees... Seems kind of vague.