Electric Vehicle effects on family and macro-economics? What happens economically when cars last 1000,000 miles on cheap local energy?

EV's can save an average family 2000 dollars a year on energy costs, and 2000 per year on automotive investment. 

That's equivalent to the national debt per capita figure of the West. 

Does that mean the West will pay back its debt?

Will prices and taxes increase to reclaim civilian wealth spared by EV's for debts?

Will the car/lorry industries halve their revenues by producing thrice as durable vehicles?
Macro
One of the big issues with EVs is that several countries collect a lot of revenue from taxes on fossil car fuels. Those revenue streams will shrink, meaning that something else will have to be taxed to make up the shortfall.
Will the West pay back its debt? Well, that's barely a meaningful question. If you're thinking of government debt (which is not equivalent to Western debt), then EVs are neither good nor bad. If revenue drops from one source, it will be taken from another source instead.
The much bigger threat to car manufacturers is self-driving vehicles. Those could reduce vehicle demand by a huge proportion, if (as expected) they trigger a growth in shared ownership of vehicles. Most cars are used for only a tiny fraction of the time. And even at rush hour, only a minority of cars are in use at any one time.
Family
EVs currently differ from fossil cars in that they have higher capital expenditure, and lower operating expenditure. That will make household cash outflow much lumpier.
However, this also encourages the move towards shared ownership of self-driving EVs, which, for those households that choose it, will remove the capital expenditure element, making their cash outflow much smoother.