1.6 altis auto is 4 speed conventional auto trans (whch u found out now)
1.8 Altis auto has a CVT
YARIS auto has a CVT too.
Both 4spd auto and CVT are totally differnt.
CVT are known to have many gears/ratios and are popular for fuel efficiency as its able to keep low rpms at most of the city driving speeds. Mostly these CVTs have 7 close gears in easy words (i would say are just ratios cause there is not proper gears in it)
Yaris CVT can be said to be superior to the old conv 4spd auto because its new tech....and most companies are shifting to it....but as per exp of many 1.6 altis owners here i have heard good fuel avg for it too.
Don't regret ur decision of buying the wrong car...1.6 altis auto is known to be at the sweet spot of power to weight ratio of this car and is a popular choice too.