Sorry, but how are we getting less? Better chassis, more torque at lower revs, better transmission, way more tech... Every review so far has indicated it is incrementally better than the 3rd gen in every measure (including efficiency, despite your above statement).
That's the cooling test. There's a very long uphill climb that they use for this. Minimum ambient temperature at a minimum speed and the vehicle must complete the climb with no temperature warnings. For downhill, I think they only check a stationary parking brake hold iirc.
So to be clear, a rear differential is most definitely in ALL tacomas (otherwise the rear wheels would not be driven) but the locking rear differential is definitely in all Canadian off road models. See...
That was my thought, too. It's effectively the same powertrain as the non-hybrid, but with the addition of a small motor + clutch. The rest is just control of the motor.
Super helpful video. I do wish they set it up for a bit better mileage, but it's a pretty nice system and I like that it can operate purely mechanical if anything goes wrong with the hybrid system.