2016 CX-5 AWD vs 2015 FWD - MPG

My 2016 averaged 37 mpg highway on a 3 hour trip to the beach a few years ago, happened on a set of new Nokian tires, never go that kind of mileage before those tires.
 
Have you ever checked for dragging brakes on your 2016 AWD? Your's has (potential) problematic rear brake calipers that stick.
Does that apply to 2016 only?
Dealer replaced rear brake pads half a year ago on my '21 and last week they told me pads are at 6 (out of 10)
 
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