Earlier quoted context omitted.
They also run on nuclear power and wind power and solar power - it all depends on what a local power grid uses. But regardless, burning fuel at a power plant is much more efficient than doing it in an ICE, so even if Teslas were powered by gasoline, as long as it's burned at the central plant, it's more energy-efficient and better for the environment.
Uh? Straight fuel -> mechanical energy conversion is less efficient than a series of fuel -> heat -> mechanical energy -> electrical energy -> transportation -> storage -> mechanical energy conversions?
Well-to-wheel efficiency for EVs is better than ICEs in every country except India currently.