It’s a Wonderful Leaf
One-Year Anniversary!

March 28, 2013

Mark D Larsen

Royal Highness
(Click to enlarge)

I am delighted to announce that today marks one year since taking delivery of my Leaf. Happy Anniversary, Ohm My!

I have never thought of myself as very materialistic, but I have to confess that I truly, madly, deeply love this EV! It is by far the best car I have ever owned: clean, quiet, comfortable, inexpensive, responsive, powerful, smooth, solid, reliable, convenient, cutting-edge... downright fun to drive. Indeed, it is sooooo enjoyable that I catch myself looking for excuses to run errands, just so I can spend more time behind the wheel.

Even then, it is not as though my daily driving around this desert community has chalked up a lot of miles. You can see the total mileage for this first year by clicking on these readouts from CarWings:

(Click to enlarge)

(Click to enlarge)

Here are the tallies when added together:

Miles: kWh:
+ 1,658.0
+ 294.2

8,232.2 / 1,513.2 = 5.4 Miles-per-kWh

Other Leaf owners will undoubtedly notice that my average efficiency is the extremely high exception to the rule. The EPA claims that my 2012 model should use 34 kWh to drive 100 miles, i.e., 2.94 miles-per-kWh. Yet to date my 5.4 average translates to only 18.52 kWh per 100 miles! Since the EPA also states that 33.7 kWh of electricity has the same amount of energy as in one gallon of gasoline, this means that my miles-per-gallon equivalent this past year has been:

8,232.2 miles / (1,513.2 kWh / 33.7 per gallon = 44.9 gallons) = 183 MPGe

Can't beat that!

Except... I can beat that: the even better news is that those kWh came from my solar array, which means that I drove all those miles with truly zero emissions! Coincidentally, I just received my latest utility bill with the final solar reading for this past year taken six days ago. Those utility stats show that my panels produced 924 more kWh than I used to power both my home and Leaf since taking delivery. (As a side note, I will grumble that, unlike in other states, our utility, Rocky Mountain Power, simply zeroes out the yearly total in March without compensating customers for any excess energy “donated” to its grid —a policy that I am adamantly urging our Utah legislators to change.) But getting back to driving on sunshine, here is how my kWh have stacked up for the first year with my Leaf:

As the graph clearly shows, the bright blue slice of the pie is 924 kWh larger than the grey and green slices combined. Below are the stats for the miles driven on the kWh in the green slice:

Tsk, tsk. Given my miles-per-kWh average, I could have driven nearly 5,000 miles farther with the extra electrons I “donated” to Rocky Mountain Power this past year. I guess I am just going to have to invent even more errands to run in my Leaf next year. Oh... please don’t throw me in that briar patch...!

Of course, one of the key questions that passersby always ask me about my Leaf is the cost to charge it. More often than not, they also want to voice the old, worn-out “long tailpipe” accusation against EVs. Using the above miles and kWh for my Leaf, the current prices in my area, and EPA data, I have calculated the following comparisons of the fuel costs and greenhouse gases:

As you can see, if I didn’t have solar panels, and had charged my Leaf from the grid instead, the GHG to generate the electricity at the power plant would have been only about 15% of the amount from my Subaru’s tailpipe and upstream sources, and would have cost less that 1/10th the price of gasoline.

That savings in fuel costs helps lessen the pain in my back pocket for being an early EV adopter. After all, I did pay a hefty price for my Leaf SL last year: the full MSRP of $37,250. Because of other deductions in 2012, my taxable income did not qualify for the entire $7,500 federal incentive, but my pending refund nonetheless lowers the cost to $31,333. Utah also offers incentives for clean fuel vehicles: a whopping $2,500 for CNG cars, but only a paltry $605 for EVs. Still, that will bring the price down further to $30,728.

If I had waited a year, I could now buy an SL model for $34,840, in which case those same incentives would lower the price to $28,318 —a $2,410 savings. Even after subtracting what it would have cost for gasoline to drive my Subaru, I still paid $918 more to drive my Leaf this past year instead of waiting to buy a 2013 model. Was it worth it? Absolutely, in my humble opinion. I have been naïvely contributing to the pollution on this planet for many decades, and consider that a bargain “fine” for my negligence. Besides, I predict that by next year the fuel savings will have eliminated the price difference entirely. Moreover, it ultimately boils down to a matter of principle. Is it worth paying more to help clean up the planet, transition to renewable, domestic sources of energy, and build a better world for future generations? As the old adage says: you get what you pay for.

In case you are wondering, I should clarify that the reason the total miles and kWh in my utility stats are less than in the CarWings readouts up at the top is because of the six days that have transpired since the last reading. Nonetheless, you can see that my average 5.4 miles-per-kWh remains the same. I would love to claim that such extreme efficiency is because I am a world-class hypermiler, but... in truth it probably has more to do with the environment than the driver. The vast majority of my driving is around town, within and among the various suburbs in this desert community, with speed limits rarely above 40 MPH and relatively few stoplights. In fact, I have only needed to drive my Leaf at freeway speeds on a few occasions: during my Plug-In Day Odyssey to Las Vegas, driving to the St. George airport, day trips to Zion National Park’s main entrance and Kolob Canyons, and one night when returning from my sister’s place in Mesquite. Yet even on those trips, I don’t think I’ve ever seen an efficiency lower than 4.3 miles-per-kWh when I pulled into the garage at the end of the day.

Another caveat I should state is that my odometer mileage likewise differs from the CarWings data. Below is a photo of what the display showed yesterday before plugging in for the night:

Day 365 of Ownership

I can only guess at the reasons for the discrepancy. The default explanation would be that I have neglected to touch the “OK” button to authorize data transmission to CarWings each and every time I started the car. However, that possibility could not account for the 300 missing miles in CarWings. There were only a couple of times when I failed to select that icon during the first few weeks of ownership, and even in those instances I immediately remedied the error after driving only a block or two. Since then, authorizing CarWings has become so automatic that it is now second nature to reach for the console screen after pushing the start button.

I suspect that a better explanation is that the odometer tallies its miles according to wheel rotation, but CarWings instead relies upon GPS mapping. Which one of those methods is more accurate, I couldn't really say for certain, but it seems likely that tire pressure, weather, elevation changes, wider or narrower turns, road surfaces and conditions could render an odometer more prone to variability. A satellite, conversely, uses fixed longitude and latitude coordinates to calculate the distance along a given route on the earth’s surface. I suppose that such discrepancies are simply an oddity for drivers with GPS systems to shrug off. Why, even yesterday, as also shown above, the trip odometer clocked 31.1 miles, yet CarWings reports that I drove 30.4. Go figure:

I am curious to see what the second year of ownership will bring. For example, will the condition of my battery pack still conforms to the polynomial curve calculated from Nissan’s published benchmarks? And after another summer of blistering heat, I’ll be most interested in seeing if the dire predictions for my capacity bars from the AZ contingent prove prophetic. Of course, by then I suspect that Nissan will have issued the promised software upgrade to make the instrumentation more accurate and reliable —which might render the kerfuffle a moot point.

Speaking of that software upgrade, I have already noticed on the CarWings web page that a new set of instructions has appeared for its settings in the vehicle. The upgrade will apparently include a second menu item which my version of the software does not have, as show in the screen dump on the left below:

Apparently, touching that button will open the display on the right above, which allows one to authorize CarWings to automatically transmit data over a 30-day period. As I stated above, touching “OK” every time I start the car doesn’t really bother me, but I know that there are some owners who deem the constant request infuriating. They will undoubtedly welcome this change with a sigh of relief and joy. At any rate, it makes me wonder what other “easter eggs” are in the pending upgrade: perchance the “percentage of charge” readout and the “80% charge now” option via the speedometer display, like in the 2013 models...? Hope so!

In the interim... Ohm My... what EVentures lie ahead!