I think you have neglected a significant loss: When you charge a battery, you must supply higher terminal voltage, Vt, than the battery produces, Vb, when there is no charging or discharging current. The difference Vt-Vb is greater the faster you want to recharge and is 100% loss. I.e. the fraction of the energy applied that is being converted to heat is: (Vt-Vb)/Vb and can be 10% with charging at the typical not over night recharge. (Slowly recharging is more efficient.) Likewise due the fact that the battery has "internal resistance" when you take energy out, more heat is generated (the RI^2 loss). As is clearly evident in that expression this loss is quadratic in the rate of discharge. (Actually greater than quadratic as the internal resistance, R, also increases with rate of discharge. - Crudely, as a typical case, pulling 2I instead of only I from the battery when the car wants more power, will increase the losses by at least a factor of 5.) If you have a "light foot" on the accelerator most of the time, this loss may be only 3 or 4% of the stored energy; but if you like the fact that an electric car has high torque capacity, even when just pulling a way from the stop light, and "burn a lot of rubber" then to impress others and you do a lot of passing, then the high current discharge losses can also eat up 10% of the stored energy by heat production. SUMMARY: Perhaps for the "typical" driver the total "in&out" of battery losses are ~15%, which you have neglected. Thus, over all efficiency in use of the fuel energy at power plant is: 0.4x0.93x0.85x0.95 = 0.30 (bold factor is the one you forgot) so there is little, if any, energy saved compared to just burning a liquid fuel in an IC motor. The all electric car could reduce the CO2 release to the extent that the wind, sun or nuclear are generating the recharge power, when compared to any fossil fuel (gasoline or natural gas) but the sugar-cane alcohol fuel reduction in CO2 is much greater. The net energy gain for that fuel is about 8, so about 12% of its produced energy was used to produce it and released CO2 (assuming that fossil fuels were used to plant the cane, harvest it, and haul it the fermentation / distillation plant). One should note; however, that there is much more energy released by burning the crushed cane than needed to run the distillation process. This excess energy is increasing used in Brazil to make electric power - about 4% of all Brazil's electrical energy now, but soon to be at least 5% as more distillation plants add electric generation capacity. To make a numerical comparison for better understanding, assume assume solar & nuclear generation produced 50% of the recharge energy. As far as the CO2 release is concerned, that is like doubling the overall efficiency from 0.30 to 0.60 so compared to the fossil fuel IC car's 100% CO2 production form the carbon in the fuel (not as much carbon in the fuel for same energy if fuel is natural gas) we have at 60% effective efficiency (for CO2 considerations) or 40% reduction in CO2 with the electric car vs the fossil fuel IC car; however an 88% reduction if that IC motor is running on sugar cane alcohol, not even including the 4% reduction of power genertion in the CO2 released to make electricity (because that 4% saving, in Brazil does not displace much fossil fuel as most of Brazil's electric power is hydro-electric power) SUMMARY: The all electric car (with half the charging energy made by fossil fuel) does reduce CO2 release by ~40% compared to car using gasoline IC motor, but if that IC motor is running on sugar-cane alcohol the reduction in CO2 release is at least twice as great. Again, I point out that if the global mobile fuel were mainly tropical alcohol, many low skill jobs would be produced, but sending billions to Arab oil producers produces very few jobs, except it does pay the wages of a lot of terrorist (opium production may pay a great fraction - but that has additional cost to western societies and greater efforts should be directed towards elimination of opium production.) I again also note, that even with clearing of some tropical forests, etc. it is not possible for sugar cane alcohol to support the current inefficient transport system. More public transport, and much more "telecommuting", special express lanes for 3 person car pools, less heavy cars, and far fewer of them, with regenerative breaking, etc. are essential before the world can get off the petroleum tit and reduce the CO2 release more than twice as much as is possible with 100% switch to expensive electric cars, many of which would still need a liquid fuel, which should be tropical sugar cane alcohol, not gasoline.