Obviously it depends on electricity prices for the cost, and driving conditions for the range, but that $20 will take you just under 300 miles. I think I’ve paid ~$25 per charge in California with its higher electricity prices, but under $15 in low priced areas (Nevada). Cheaper than gas, but not necessarily if you count the higher price of the car. Effectively Tesla prices expected gas savings (and the government credits) into their sales price. I like the car and would recommend it, though it is probably priced higher than it deserves (even after applying any credits). In my book you’ve got to have some other reason to justify having a Tesla than just money savings or being eco-friendly. It’s performance is what pushed me over the edge, as it accelerates faster than low-end Porsches (though the Porsche will out handle a 3 any day). As one friend said, he’d drive his S even it it ran on baby harp seals.