In comparing the efficiencies of petrol engines to engines from electric vehicles, I may have overlooked noticing any factoring in of costs of huffing/smoking the exhausts of the two types of vehicles. (Obviously some choose to efficiently use petrol exhausts for suicide.) Years ago TV news programs were regularly providing the smog indexes for various cities on a daily basis. I drew the possible false conclusion that my lungs might be healthier (and my life possibly longer) in an area with less smog.
A possible significant corollary is that (though fought tooth and nail by the tobacco profiteers and other deniers for years), people have finally generally concluded that the use of tobacco, which is an addictive legal drug, (even second hand {since we are really talking about polluting fluids [i.e., air] around those in the household, job site, motor vehicle, etc.}) probably causes cancer. Many areas have trampled the "rights" of tobacco polluters by banning their use in establishments. We are probably better off for such. To evaluate tobacco on a cost benefit analysis, it seems appropriate to consider not just
"Worldwide, tobacco use causes more than 5 million deaths per year, and current trends show that tobacco use will cause more than 8 million deaths annually by 2030.3
In the United States, tobacco use is responsible for about one in five deaths annually (i.e., about 443,000 deaths per year, and an estimated 49,000 of these smoking-related deaths are the result of secondhand smoke exposure).1
On average, smokers die 13 to 14 years earlier than nonsmokers"
http://www.cdc.gov/tobacco/data_statistics/fact_sheets/fast_facts/
but the direct costs of health care treatment for the slow, expensive deaths, but the direct costs of health care costs for those various other diseases.
Cause and effect has constantly been the argument of the deniers/doubters.
You cannot have millions of heat producing (that is dangerous to the plants needed for food we directly consume and for food we indirectly consume from the consumption of meat [http://www.sciencedaily.com/releases/2010/01/100107132543.htm]), carbon dioxide producing [http://epa.gov/climatechange/science/causes.html], toxin releasing petrol engines running in exponentially increasing numbers without damaging the fluids (needed for our minute by minute survival) they are blowing their wastes into.
When you want to get muddled about efficiency of electric vehicles to petrol engines, consider these additional costs in making a choice as to what you support.