Tesla S has a three phase AC induction motor, 1 speed gear (9.73:1). It comes with 60 or 85 kWh lithium ion battery. 56,800 units have been sold worldwide as of Dec 2014. The EPA rates energy consumption as 237.5 Wh per km, giving a combined fuel economy of 89 miles per gallon of gasoline.
Tesla S 60 kWh
208 / 233 miles (EPA/NEDC)
Tesla S 85 kWh
265/ 310 miles (EPA/NEDC)
In their marketing they claim this as 0 CO2/mile. Since the electricity can be made by different methods that is fair, moving cars to electric power is one way to substitute renewable energy for ‘fossil fuel’.
At the moment though much of our electricity is produced by burning fossil fuels, we need to consider another number then, how much CO2 is produced in delivering a kWh of energy to our home.
That is a a bit complex, but lets say it depends on the energy mix in your country. In France it would basically be nuclear powered. 🙂
France has 76.6 % Nuclear power, 10.2% Hydro, 4.47% non-hydro renewable, 4.08% coal, 3.69% gas, 0.58% Oil.
In the UK electricital power is mainly generated from burning gas, coal and oil, with 15-20% produced from nuclear power.