15-16 mpg

I am just wondering why lately Ive been getting 15-16 mpg.
Tires are at 32. Premium 91 / 93 octane (depends on which station). Driving habits are the same. New tranny fluid at 55k per MID....Does something need to be aligned in the motor? I also had the throttle body cleaned up at 56-57k

Any thoughts? 2009 TL with 66k.

Appreciated :-)