2017~2021 AWD versus FWD

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2016 CX-5 (white), 2019 CX-5(red), 2019 Miata (white)
#1 Check and adjust tire pressure accordingly.

Then, try it rolling it at say 15 mph in both D and N to see if you have dragging brakes or if its just drivetrain / engine braking.
Tire pressure is good, I usually keep them at about 37 psi.
At 15 to 20 mph the wheels roll freely in neutral (N) and when in drive (D) there is a bit of resistance.
 
This is from 2016.....

"Mazda’s i-Activ predictive AWD
Mazda has introduced a predictive form of all-wheel-drive on its subcompact (CX-3) and compact (CX-5) crossover SUVs. It will also be on the next generation full-size Mazda CX-9 crossover later this year. Normally the i-Activ system delivers 98% of the power to the front wheels. An array of sensors looks for impending tire slip and begins to shift power to the rear wheels before the driver notices.

According to Dave Coleman, Mazda development engineer, in bad weather there’s a time of limited traction where the tires are just beginning to slip that can be noticed by the car’s sensors (but not yet by the driver), and acted upon, so that power quickly begins flowing to all wheels. Mazda calls this golden moment the “control area” (illustration above) where the car can intervene.

The predictive part comes from all the sensors working together, not just wheel-spin measurements. Mazda says the car reads 27 channels of sensor data 200 times a second to determine when to begin powering the rear wheels. The sensors include inside and outside temperature, wipers on/off, road incline, yaw (off-center movement left or right), steering wheel effort vs. angle, individual wheel speeds, position of the gas pedal, brake fluid pressure, transmission gear, and dynamic stability control activity. The only sensor Mazda added for i-Activ was oil temperature.

The “condition biasing” sensors alert the car to obvious possibilities: Cold weather means it could be slippery, wipers on mean it’s probably raining and maybe snowing, and an uphill incline means weight has transferred from front to back wheels with possible loss of traction. The amount of steering effort relative to the angle of the steering wheel (image right) correlates to slippery conditions; it’s easier to turn the wheel on a snowy road. That would bias the computers to order up more traction in back.

In order to quickly share power with the rear wheels, Mazda employs an electromagnetic activated coupling between front and rear wheels. To avoid a jerky switchover, Mazda runs a small “pre-load” of power, 2% of total, to the rear wheel."
 
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