Does using tiptronic transmission save gas?

I got an automatic 05 acura tsx with the sport shift tiptronic thing in it. My question is, can you save gas using it? If yes, how should I use it to maximize my MPG? I've heard about shifting it to the highest gear when going slow, but how slow exactly? I don't really suppose I should be in 5th gear while going 30 mph, am I? Also, does engine braking with it save gas?