More efficient at a particular moment in time. There is a lot of other baggage in the background, such as manufacturing, and wear and tear. The motor in most cars these days are good for 200k miles. What last’s 200k miles on a hybrid? Certainly not the battery.
The only thing I envision that will change the equation will be a coating or other product that will turn heat directly into electricity. That, will be the game changer, not storage.
The vehicle operational efficiency is always significantly higher as evidenced by the better gas millage. All of that extra weight doesn’t seem to be an issue.
No doubt there are times when a hybrid is way more efficient that a standard car.
Also, I wonder if the internal combustion engine in a hybrid has to work less, too since the electric engine assists the gas engine.
There are probably other wear out factors since the gas engine has to charge the battery sometimes.
Hybrids are still relatively new in their life cycle.
ROI is the question.
And all electric is a different story since it is charged by the power plant.