I think all cx-70s are hybrids, the non-PHEV versions are a "mild hybrid" with a smaller battery and an electric motor that assists the engine for more power and to restart after shutting down at stop lights check your owners manual for more info.

 

Buy why only when touching brakes if slow down on own no noise?

 

I hear the whining noise whenever I slow down, whether using brakes or just taking my foot off of the accelerator.

 

I hear it when coasting and the engine shuts off.

 

That sound was the first question I had to the Salesman while test-riding the CX70. I was assured it was normal.
Still hear it to this day and don’t pay it any mind………..part of the drivetrain to electric motor connection I assume?

 

Remember, that sound that it makes is the reason that the CX-70 gets such great fuel economy for a vehicle its size!