You may have noticed one obvious question about the Nissan Leaf that I did not address directly last week: How far can you drive this car on a full charge? Well, the truthful answer is, it depends. A lot. On everything. I've brought up a number of issues that affect the range: air conditioning, hilly terrain, high-speed stop-and-go traffic, and aggressive driving. There are others, like rain, that have a fairly minor impact on range, and then there is the main determinant of range - the temperature. I'll get into that in more detail in a minute, but first, I'd like to vent for a moment about one aspect of the Leaf that surprised me when I was first looking at it - its color choices.
I know, this is vain and superfluous and all of that, but the Leaf only comes in six colors and none of them are green. My wife noticed it first. It's a green car - a LEAF - that does not come in the color green. The way we figure it, there should be at least two shades of green available: a darker forest green and a lighter green, maybe neon, that would really make a statement. While I'm being hypercritical, why are the other color names so boring? Why not mix things up a bit and make it more fun for your primary market segment by renaming the colors for the environmental fanatics that are going to buy this car? Blue Ocean is okay, but how about Silver Maple or Arctic Snow or Autumnal Fire for some of the other colors. I'm sure Nissan marketing could have come up with some better color names if they gave it even a moment's thought, and why not? This is a fun new car that is blatantly Eco-friendly. Nissan should add to that experience every way they can.
Playing the 'Guess How Many Miles are Left in the Battery' Game
Returning to the matter at hand, the range of the Leaf is significantly impacted by the ambient temperature. Up here in Madison, WI, the winters can get pretty cold and stormy. They don't get nearly as bad as further north in the U.P. or Minneapolis or Canada, but we'll still get an occasional 20-inch snowstorm and at least a handful of days below zero each year. However, the first winter with my Leaf in 2012 was uncharacteristically warm. (We planted part of our vegetable garden in late February, and it survived, which is quite unusual for a 5a climate zone.) Driving the Leaf was fairly uneventful, and it was quite nice to see the range creep up from 75 miles reported on an 80% charge to 85+ miles as the weather warmed up.
At first I charged everyday to play it safe while driving in the semi-cold winter months, but as I gained confidence and a bit of reported range, I started charging every other day. As long as I had 40 miles left on the GOM in the morning, I found that I could easily get home from my 23 mile round-trip commute with at least one full bar of charge left.
Let me explain that a bit more. Like most modern cars, the Leaf has two ways of reporting the range, although it's for the battery instead of a gas tank. The battery charge level is shown as a set of twelve bars, so one bar equates to approximately 6-9 miles, depending on conditions. Not the best resolution, but it's a fairly accurate measure of the charge left. The estimated range is shown as miles-to-empty, and is commonly referred to as the Guess-O-Meter or GOM. It has better resolution, but it bounces around depending on immediate driving conditions and seems to be eternally optimistic at full charge. The GOM gets more accurate the closer you get to reality, a.k.a. zero miles left.
You can imagine the pleasant experience of starting off with a new Leaf at a certain range and then getting more range as the summer gets warmer. If you recall, last summer was hot and long. My GOM peaked at 90 miles on an 80% charge for May through July. By the time the weather started to get cool enough to fall back to charging everyday, it was mid November. The Leaf could still do two 23 mile trips on an 80% charge in temperatures as low as 40℉. I thought that was pretty good, but below that temperature the range dropped enough that I didn't think I could make a second trip.
There were other reasons to charge everyday at that point. We have a saying in Wisconsin. If you don't like the weather, just wait a minute. I didn't want to take the chance that the next day was going to be so much colder that I'd come up short on my drive home. I also figured charging everyday was better for the battery than charging to 100% to allow me to get two commutes in on a charge. Finally, the battery has a heater that kicks in if it gets too cold so it doesn't freeze up. I didn't want the battery heater draining too much charge, and the manual recommends plugging in when the Leaf is parked in cold weather because the heater will run off the plug's power instead of the battery. To play it safe, I charged every night once the daytime temperature dropped below 40℉.
The Iceman Cometh
This last winter was a much more normal Wisconsin winter with a handful of days going below zero and most of January through March spent below freezing. Consequently, my GOM spent most of its time below 75 miles on an 80% charge, and after an entire day and night stuck at 0℉ and waking up the next day to -4℉, it hit a low of 62 miles. Those are the moments that bring truth to the quip that to drive the Nissan Leaf, you have to get used to driving as if you're always almost out of gas.
The initial shock wore off fairly quickly, though. My commute is short enough, and I made it to work and back without any issues. I even had 32 miles left on the GOM when I pulled into my garage, which was a pretty normal 30-mile round-trip difference for my 23 mile commute. One thing that becomes quite obvious in the winter is that the temperature is so important to the Leaf's range that it is built into the GOM algorithm for estimation. My garage can be 10-20 degrees warmer than it is outside, and as the car gets colder for the first few miles of driving in the morning, the GOM miles go down noticeably faster than normal as it adjusts to the outside temperature.
Another thing the GOM does to try to get the range right is use the previous trip's miles/kWh measurement to estimate the new range after charging. It was really the previous day spent at 0℉ that resulted in that 62 mile estimated range. The day warmed up a bit and, consequently, the mileage was a bit better, so the next day's GOM estimation was 64 miles. This behavior is fine when the weather is warming up, because you'll have a bit more range than you think, taking into account the GOM's optimism. But you definitely have to watch it when the weather is cooling down, or you could come up short.
You Can Have Heat, But It'll Cost You
The heater will also impact the range, of course, and a bit more strongly than the air conditioner in the summer. That's partly because an electric heater is less efficient than an electric air conditioner, and partly because the battery is already at a disadvantage from being cold. Whereas the A/C would take about 10% off of the range, the heater would take off more like 15-20%. Come to think of it, the heater also has to work harder because the A/C only had to cool down the cabin 10-20 degrees in the summer, but the heater has to bridge a gap of 40-60 degrees in the winter.
At any rate, I ended up not using the heater much, except for defrosting. Before getting the Leaf, I spent six years trudging through 12-inch snowstorms and freezing cold when I used to walk over a mile to get to work, so sitting in a cold car doesn't really bother me. I put on my wool socks, ski jacket, and ski gloves, and I'm fine. But I'm a crazy person. Even though the Leaf has plenty of range in cold weather for my commute, I forgo the heat to save the energy. That's just me, though. I know normal people will want to be more comfortable than that, and for them, I'd say go ahead and use the heater. As long as you take the range reduction into account, there's no problem. The Leaf also has a heated steering wheel and heated seats, and they're much more efficient than the forced air heater. That should keep your most important parts warmed up. Also, the 2013 Leaf has a more efficient heat pump instead of the resistive heater on my 2012, so the range reduction shouldn't be so bad on newer models.
As for the climate controls themselves, they are just as easy to work as in the summer. When you switch from A/C to heat, all you need to do is adjust the temperature once, and then you can hit the 'Auto' button when you want to use it. When you need to defrost, there are dedicated buttons for that. One for the front windshield, and one for the rear windshield. When you hit the front defrost, it automatically adjusts the temperature and fan and redirects to the windshield vents, so there's no fiddling with multiple knobs and buttons. The Leaf is the first car I've had with these kinds of features, and I have to say, they are really nice. That's one less thing to think about.
Does Your Car Have an App?
That's right, the Leaf has its own smart phone app. With it I can check the charge level and range left on the battery, and if it is plugged in, I can start the charger and monitor how long it will take to charge. Normally, that's not terribly useful because I use the charging timer and the car charges for a specific time during the night whenever I have it plugged in.
What can be useful is the ability to turn on the climate control about five minutes before I leave for work in the morning. Then the car runs off of the charger power to warm up the cabin without using any battery power, and I have a nice head start on my drive to work with a warm car.
On top of that, I can setup the Leaf to send me various email or text messages telling me when charging has started and finished, telling me when the climate control has turned on if I'm using the climate timer, reminding me to plug it in if I forgot, and notifying me if the car was unplugged while charging and I haven't driven off within five minutes. I bet you can guess what that last one is for. Suppose I'm at a public charging station and someone comes along and decides to unplug my car before it's done charging. I'll get an email letting me know, so I can go see what happened instead of coming back in an hour to an uncharged car. I've never had this happen, partly because I hardly ever have the need to charge at public stations. But having the feature is nice, and it probably helps curtail bad behavior as long as people know that if they unplug someone's Leaf, it won't go unnoticed.
Playing in the Snow
Okay, getting back to the main topic, winter isn't only about the cold. Wisconsin also gets a decent amount of snow. Last winter we had a couple of storms that dumped over six inches of snow, and one that unloaded 20 inches on us over the course of 24 hours. I didn't actually drive that day because I spent the entire day shoveling to keep up with the storm. Most of the city was pretty much shut down anyway. But when I did drive in snow, the Leaf performed admirably. It has ABS, traction control, and Vehicle Dynamic Control (VDC), which really help when driving in slippery conditions. The VDC applies the brakes and varies the speed of the motor to maintain traction when the car senses the wheels slipping, and I've had it engage a few times when driving in the snow. It's always done a good job of assisting in maintaining control of the car.
Additionally, the Leaf is no lightweight, coming in at 3300 pounds, even though Nissan did everything they could to reduce its weight. A lot of those pounds are in the battery, which is mounted in the center of the car under the seats. This placement gives the Leaf a nice low, balanced center of gravity, resulting in less body roll when turning and making it less likely for the rear end to slide out. Between the weight and control systems, I've never gotten close to losing control or getting stuck in the snow.
Capable, Within Limits
I knew going in to this experiment that the Leaf would suffer in cold weather. I'm not at all surprised by how much range it loses from cold weather and heating the cabin. In fact, I'm pleased that it handles the cold weather as well as it does, and it does an excellent job of driving in the snow. The range in the winter is more than enough for my commute, but I'm sure it won't be enough for everyone. If you have to drive near the Leaf's summer limits with a range of 85-90 miles, then winter will pose a significant challenge with a range that can go down to 50 miles in severe weather. Being able to charge at your destination will greatly extend its range, and you'll be able to preheat the car at both ends of your trip, giving it a bit more of a boost.
Looking a little farther into the future, if the Leaf's range was double what it is now, winter driving wouldn't be an issue for almost anyone. I'm sure that will happen. It's only a matter of time before battery technology advances enough to put a 50kWh battery in a car that's less than US$35k, and motor, braking, and climate control efficiency are improving at a rapid pace. When that happens, one major shortcoming of EVs will have been eliminated, and they become much more viable for many more people.
That's all for this week. I've yet to cover a couple other features of the Leaf, like energy monitoring and the tree-building game. I'll talk about that next week along with maintenance. Oh come on, I'll think of something to say about it.
The Rest of the Leaf Series:
Part 1: The Acquisition
Part 2: The Summer Drive
Part 3: The Winter Drive
Part 4: Frills and Maintenance
Part 5: The Data
Part 6: The Future
Part 7: The Energy Efficiency Meter