If someone had a daily round trip commute of 40 miles (without destination charging) they wouldn't burn any gas at all in the gen 2 Volt. If they had the Prime they would be burning gas every day. This scenario will the case for a MAJORITY of drivers, hence why I said the Volt 2 is more efficient overall.
Efficiency refers to the fraction of useful work from an energy input. You are saying something different -- that a Volt uses less petrol in 40 miles than a Prime. That is not in dispute.
You mostly err, however, in thinking that a Volt traveling 40 miles (a very good case scenario for a Volt) in EV emits less CO2 than a Prime.
The Volt will consume about 350 Wh/mile * 40 miles = 14 kWh of wall electricity
The Prime will consume about 6.3 kWh of wall electricity and 15/54 gallons of petrol
Using the CO2e equivalent of 25 pounds (11.34 Kg) per gallon petrol, the grid has to supply the Volt with electricity at no more than
(11.34*15/54)/7.7 = 0.41 Kg CO2/kWh. Go ahead, find the places in the US where that is true.
https://www.energyvanguard.com/blog/how ... lectricity
Are you including the pollution generated with the whole process of getting the gas to the gas station (from oil in the ground to gas station and all steps in between)?
Seems we have a conflict of sources here, my source claims EVs in general pollute less than even a 50mpg hybrid in most states. I think I will stick with my source!
What you fail to realize is the grid will only get cleaner, there's a limit on how efficient any ICE can be, in the end electric propulsion will win in terms of efficiency and pollution. So why not start now? Why not go for the car with the bigger battery with more electric miles driven?!
It's not all about pollution anyway, aren't we supposed to be trying to reduce our dependencies on oil? Seems to me the best way to go about that is to drive more electric miles which is exactly what the Volt 2 does!
Petrol is well to wheel, adjusted for tar sands;
Electricity is power-plant to wheels. I don't know how to account for mining and transport
Your UCS source uses a LEAF as the comparison vehicle. Read the full article. The volt is some 15% worse. Says so, right in your source, using the EPA data.
Reducing oil dependence is a very good thing, as is reducing GHG emissions and improving air quality. The Volt can do quite well for the first goal depending on how the car is used, does OK but inferior to the Prime in GHG, and does poorly when it comes to air pollution if your regional grid has a coal component.
And in even the area where the Volt is supposed to shine, it is a YMMV depending on use. It is common for Volt owners to also own an SUV for long distance driving. Their data is garbled since they do not include the SUV in their oil consumption. My long distance driver is my Prime; I use it for 90 mile work commutes and 250 (each way) mile trips. The 250 trips are ~ 32 times a year, and the work commuting is 130 times a year. It works out for oil consumption (according to EPA):
Long trips: 32 trips * 225 miles/trip / 54 mpg = 133 G
The work commutes: 130 trips * 65 miles/trip / 54 mpg = 156.5
For a total EPA oil use of 290 Gallons per year.
If these trips were in a Volt:
Long trips: 32 trips * 197 miles/trip / 41 mpg = 154 G
Work: 130 * 37 miles/trip * 41 mpg = 117.3
For a total EPA oil use of 271 Gallons a year
Volt advantage: ~ 19 Gallons a year
Volt: 16.7 kwh/trip * 162 trips =2705.4 kWh
Prime: 6.3 kWh/trip * 162 trips =1020.6 kWh
Volt disadvantage: 1685 kWh
In my area a kWh is about 2 lbs of GHG emissions
A gallon is about 25 lbs of GHG emissions
Net, the Volt emits (1685*2) - (26*25) = 2720 lbs more per year CO2e
are each about a gram per kWh from my local power plant,
So the Volt emits about 1685 grams extra Nox and Sox per year.
Unsaid so far, but not to be disregarded:
The Prime is less money to buy. That money put into a PV array swings things wildly in favor of the Prime. All of my home electricity and EV miles are from my home PV, and excess is sent to my neighbors. How about you ?