So sure the Roadster can hold what, 6 gallons? Like an econo-box. And weighs 2 1/2 - 3 tons. Much of that in battery.
Yes, weight is still the big issue.
For the most extreme comparison, a Bugatti Chiron gets an EPA 11 MPG so the roadster is arguably the equivalent of a 56 gallon fuel tank where the Chiron is stuck with 26 gallons.
PS: A better comparison would be a similar ~200,000$ two seater but none of them are optimized for fuel efficiency.
A bit of a tangent but it'll be interesting to see what effect an all electric vehicle future has on the design of roadways, bridges, etc. I imagine that many things will need to be rebuilt to handle the additional load.
Raising the average vehicle weight from 1.5 to 3 tons will definitely have an effect.
I would guess electric cars are still negligible in that metric, though.
EV’s hit 2.5% of total sales in 2019. 2020 is likely going to be odd, but scaling production still seems to be the bottleneck.