Longest, most descriptive review video so far..

Power seats are useless to me.
One more thing to go wrong and they're way slower than going it manually. I'm not that lazy or old.

 

It would probably more accurate to say it switches to Atkinson cycle when there is a lack of demand. But even to say it switches is misleading. It seems that many think something magical happens when this engine 'switches' to Atkinson.

This engine is fundamentally the same as all other (Toyota) engines with VVT (D-4S notwithstanding). The only difference is that the VVT operates over a wider range; hence, VVT-iW.

5VZ-FE closes intake valves 42° after bottom dead center.
1GR-FE VVT-i can close from 10-60° ABDC.
2GR-FKS VVT-iW from 25-105°.

When does it suddenly become "Atkinson"? At 61°? 90°? The 2015 Prius can only go to 102°.