1. Yes, when measuring only energy efficiency, and when some of the energy comes from something other than liquid fuel, fuel cost is meaningless.

2. Yes, when only trying to measure energy efficiency, cost is irrelevant. Energy “depletion” is goobledegook. Perhaps you mean energy use, which is reported in kWh / 100 miles. Perhaps you mean cost efficiency, a different concept.

3. I’m so glad that you finally understand how energy efficiency works. Good luck with your homework.

Assigning a cost to energy depletion, for a plug in operating in the charge depletion mode, is gibberish. If you say so.

Class dismissed.

I’m very hesitant to post this, as I don’t think you are clear yet that energy efficiency and cost should be considered separately, as soon as you introduce hybrid transportation (yes, EPA is running about a decade late on updating their webiste). But, I’m all for transparency and accountability.

Hint on the costs and dollars. Just as you can do average energy efficiency on a vehicle cycle basis, you can SEPARATELY do averge cost on a vehicle cycle basis, in some common unit, such as $ / 100 miles. SImple take the two parts of the energy efficiency calculations I did for you and mulktpliy each part by the cost per kWh (cost of gas/kWh is $/gallon/36.4). The cost / 100 miles for different vehicles will fluctuate hugely over time, as gas prices are extremly volatile and much more volatile than electricty prices.

Thus, average cost of energy is a very poor method for trying to directly compare vehicles, as it varies widely. Because electric prices are more stable than gasoline prices, if you want more consistent costs with lower likelihood of nasty surpises and cost spikes, more electric drive and more battery is clearly superior to less electric drive and more gas on a cost stability basis.

Even if we went to 100% non-gas electric everywhere in the US, we would still want to consider cost separately from energy efficiency, as electric rates vary quite a bit from region to region in the US.

Sorry. MPG just isn’t adequate any more (it never really was, but now it’s truly broken).

You’re mixing fuel use with dollars and cost and refering to energy “depletion”, who knows what you mean by that, which is all gibberish.

What we are trying to measure is the average total energy used at the vehicle level to go a measured distance for a complete vehicle cycle. It’s not rocket science, The official US DOE/EPA metric for that is kilowatt hours (kWh, a measure of energy over time) per a set number of miles (KWh / 100 miles), at the vehicle level for an everage over a complete vehicle cycle. For the gas portion, simply convert the gasoline energy to kWh and measure the miles that energy takes you. You already reported the gas to miles portion of the Volt and I already did the simple conversion for you of gasoline energy in kWh (1 gallon gas = 36.4 kWh per the US DOE (actually I cut you and GM some slack and gave you 36.6)). Are you trying to tell us that the US DOE is wrong?

Your work is also riddled with mixture assumptions, while I already reported the kWh /100 mile results for regular and plug in hybrids and electric cars, using certified EPA-06 vehicle cycles that already considered all combinations actually used over a complete vehicle cycle.

The old EPA method of MPG is useless for comparing all types of vehicle directly against each other, unlike using kWh / 100 miles, counting ALL at-vehicle energy use for the COMPLETE vehicle cycle, which allows for direct comparison of vehicle cycle energy efficiency for all types of vehicles. I’ve already done the analyses and reported the results to you for direct comparison, with an interpretation of how various automakers are positioned relative to each other.

I do agree with you that MPG is bogus.

Costs and dollars are a completely separate topic. We are still trying to get you to understand measuring vehicle cycle energy efficiency, the energy used at the vehicle to move it for a measured number of miles for the complete vehicle cycle. kWh / 100 miles is the official metric for that.

Lets compare with an imaginary Plug-in Prius with a 16 mile AER and a charge sustaining mileage of 48 MPG. It would burn gas for 32 miles of the test in charge sustaining mode, and kWh for 16 miles in charge depleting mode. If you run the numbers, the imaginary vehicle gets about 52 MPGe. And like the Volt, if you ignore the depletion of the KWh, you could claim 72 MPG. But it would also be a bogus claim.

And finally, the Tesla would “burn” 10 KWh over the 48 miles and would thus get 77 MPGe. This method of comparison is simple and accurate from the “fuel cost” perspective.

http://reviews.cnet.com/8301-13746_7-10037173-48.html

Adding in the actual energy required from gas to move the Volt beyond 40 miles allows for direct comparison with others vehicles that have a range of greater than 40 miles (all of them). Leaving it out prevents comparison, except for the battery only portion of operation ( that’s only 11.76% of the Volt’s total range).

Why don’t you just use the official EPA metric for electric, # kWh / 100 miles for the full vehicle cycle average, as the Volt is 100% electric drive?

What happens outside the vehicle has absolutely nothing to do with vehicle efficiency and vehicle efficiency is what we want to compare. The in vehicle losses are already included in the analyis. Your figures are only for the first 40 miles for the Volt. Adding in the actual energy in the gas to go beyond 40 miles is correct, as the vehicle requires gas use when driven beyond 40 miles.

Unless you are looking at each vehicle’s complete vehicle cycle when comparing vehicles you are leaving something out, in this case, the lowest efficiency part of the Volt’s opeartion and are lying to consumers. You think we are stupid?

Your approach only compares part of the Volt operation (the most efficient) to the Tesla’s total average efficiency and tries to bring in information (nuclear power plants) that has nothing to do with vehicle efficiency. Who’s bogus?