So, for those still interested in the numbers, our first full month of Volt ownership is complete and I have some preliminary fuel consumptions and electricity bill info. It's a long post, but here's the nuts and bolts.
Electricity consumption is of course variable so all I can do is compare last April to this April. Obviously THIS April is expectedly higher due to the EV charging (which, FWIW, was almost exclusively done during off-peak rate times) but of course other consumption year to year can vary as well so the difference may not be an exact calculation of how much the car used obviously, but close enough.
LAST April (2016) we used 439KWH, off peak.
THIS April (2017, with the Volt charging regularly off peak) we used 766KWH.
The difference is 327KWH. At roughly 10.5-11.0 KWH per full charge (I'll use 10.75 for the math) this comes out to almost exactly 30 charges, and hey, 30 days in March, so that sounds pretty much right on. There were days that we did recharge and use a second full (or near full) charge on a weekend so the EV numbers might actually be a bit larger, but I didn't track it exactly and it just makes things harder to calculate, but they would only help the numbers, not hinder, but again, I'm trying to be real-world here.
At 8.7c/KWH that comes out to $28.44 in electricity. Less than the cost of one tank of gas in the Volt.
Assuming each full charge took the car an AVERAGE (some charges got more, some got less) of 50KM, over 30 days, the car would have travelled 1500KM on electricity alone. As mentioned above, it probably travelled more than that on EV mode, but again, it was impossible to track it exactly, and I'm happy with an average for this month.
That works out to $0.018 per Kilometer for operating cost on electricity.
For comparison, a Hybrid burning 5.0L/100KM, assuming current average $1.10/L gas costs, would have burned 75L of gas to cover the equivalent number of EV miles the Volt travelled on electricity, and that would have come at a cost of $82.50, or $0.055/KM.
That's a 101% difference, so in short, running on electricity costs half of even a super fuel efficient hybrid. And gas, on average, was over $1.10 last month, but I used current pricing instead of past pricing, so in reality those numbers were actually even slightly better.
FWIW, with the changeover to the summer Time Of Use metering as of May 1, the overnight (off peak) electricity rates also went down from 8.7c/KWH to 7.7c/KWH, a 12% drop, also bolstering the EV savings calculations.
Yes, we did burn gas as well, but those numbers are separate from the "pure EV" numbers above - the car travelled far more than 1500KM this month, actually closer to about 3800KM.
I haven't yet calculated the average (mixed EV & gas) L/100KM (my wife needs to fill up tomorrow so I can do so) but it's looking like it's going to come in under the 3.0L/100KM point according to my gas stats program on my phone. Other interesting stat - the car travelled an average of nearly 1000KM between gas fillups.
The numbers are super impressive when compared against our old car, her Chrysler 300.
3800KM at it's average 12L/100KM consumption would have been 456L of gas last month, at a cost of just slightly over $500 based on the $1.10/L calculation I used earlier.
The Volt, in comparison, I expect to see a final gas cost around $150. Add in the $28 in electricity and our first month of operating cost was roughly (and I stress roughly, but I'm using simple estimates here) $180.00.
So, very long story short, we saved roughly $320.00 last month in operating costs vs her old car.
Using the above full month estimates and comparing the overall monthly mileage total to a Hybrid instead, at a 5.0L/100KM fuel consumption figure, a Hybrid would have burned $228 in gas (based on last months $1.20/L), so we saved $48 vs a Hybrid.
All of the above numbers will trend significantly better towards the Volt when my wife gets the charging setup at work. That's still ongoing. Even without it, the numbers are still very favourable however.