The Nissan Leaf takes on an uphill road in mountains east of Seattle. Ups and downs can affect the car's estimated range.

"Your mileage may vary" ... That old phrase is even more relevant for the newfangled Nissan Leaf electric vehicle, which has an advertised range of 100 miles on a charge. In fact, the mileage depends quite a bit on your driving style, and the numbers can go up and down in the course of a drive. Yes, it's possible to get 100 miles or more from the Leaf. But if you're the kind of guy who keeps the car on the road even if the needle is near the "E" mark, you might have to change your ways.

The "needle" on the Leaf isn't a physical needle, but a readout that appears right in front of the driver on the dashboard, as well as on the energy-monitoring displays you can bring up on the center console's touchscreen. You can even bring up a map with two concentric circles, estimating how far you can go in normal mode (in which the Leaf acts pretty much like a normal car) and in eco-mode (which tweaks the car's response to optimize the power savings).

To arrive at those estimates, the Leaf's electronic brain factors in how you've been driving the car up to that point, as well as the load that's being put on the electric motor at that moment. When you're coasting downhill, you can actually add to your range.

Luxury in a Leaf
Let's take today's drive as an example. The first seven miles were so effortless that the range went up from 96 to 103 miles in eco-mode. But that was the day's high mark: As multimedia editor Jim Seida and I drove up through Western Washington's Issaquah Alps, the numbers were driven down. At the 19-mile mark, when we passed by Snoqualmie Falls (where the TV show "Twin Peaks" was filmed), the Leaf's screens told us we had only 45 miles of driving left.

Those numbers quickly crept up again during our descent from the mountains -- back to a range of 60 miles. But we lived a little too luxuriously on the way back: Turning on the heater and the fan ate into our electrical reserve, and by the time we returned to Redmond, we had an estimated 24 miles left in the batteries. A 47-mile trip took away 72 miles of my original estimated range. Good thing we didn't go all the way to Snoqualmie Pass (which would have been a 100-mile round trip).

If we were true hypermilers, we would have been able to get by with less electricity -- but instead, we drove the Leaf like a normal car. The bottom line is that Leaf drivers will have to think about their driving strategy: If a visit to the neighborhood grocery store is your only stop of the day, there's nothing to worry about. If you have a 25-mile commute to work, and you have to stop back at home before going out to an evening engagement that's 5 miles away, you just might be thinking about charging up while you're at work and using the eco-mode setting.

Guilty as charged?
Speaking of charged up, I received some sharp comments about the fact that I topped off the Leaf's batteries on Monday by plugging into an outlet at the office parking garage. "The main problem is you are stealing someone else's electricity," one commenter wrote. Another writer was critical of the whole electric-vehicle concept: "When that big 4x4 is blocking you in, it will be me. The hand waving you forward will have an extended middle finger. Just for you EV elites."

Such responses show that the move toward "electrification" of the automotive industry could run into a few culture clashes along the way. What principles will find their way into electric-car etiquette, or corporate and governmental policies?

I'd like to think that places like the Oregon city of Hillsboro (where Intel is the largest employer) are leading the way in the creation of charging-station havens. I'd like to think that the EV Project, which is due to install 15,000 charging stations over the next year with $115 million in support from the U.S. Department of Energy, is on the right track. But for some people, having taxpayers foot the bill for the installation of charging stations would be going too far.

The way I see it, the success of the Leaf will depend on the spread of those charging stations -- not so much because they're necessary, but because that will reassure folks like me that there's a backup plan just in case the Leaf sometimes doesn't go as far as you expect it to. I may find out about that firsthand tonight, when I take my loaner Leaf on a final 19-mile drive to turn it in. Stay tuned for the next chapter. ...

Click here for the next chapter: 'I Was Nagged by My Electric Car'

You can try the Leaf out for yourself during the "Drive Electric Tour," sponsored by Nissan. The next stop is in San Francisco. Keep checking our Green Innovation section for more about electric cars and our "Electric Road Trip."

Connect with the Cosmic Log community by "liking" the log's Facebook page or following @b0yle on Twitter. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

Msnbc.com's Alan Boyle looks for a parking space near a plug-in for his all-electric Nissan Leaf.

Someday, millions of electric cars will be on America's roads, gulping down the juice from tens of thousands of charging stations scattered around the country. But "someday" isn't here just yet -- which is why I'm so happy I found a space in the parking garage next to an electrical outlet for my Nissan Leaf.

Over the next couple of days, we'll be putting the all-electric Leaf to a real-world test here in the Seattle area, thanks to Nissan's nationwide "Drive Electric Tour." The folks at Nissan were kind enough to lend us a car for a couple of days in between their Seattle and San Francisco stops.

It's one thing to drive the Leaf around on a two-hour test drive, as CNBC's Phil LeBeau did in July, but quite another to work it into your day-to-day driving routine. Fortunately, my routine is a perfect fit for the Leaf: I have a commute of as little as 7 miles to work at msnbc.com's mothership in Redmond, Wash. Because the Leaf has an estimated range of 80 to 100 miles per charge-up, I could easily bring the car back to Nissan on Tuesday without ever plugging it in.

But where's the fun in that?

This was an opportunity to take the neighbors for a ride, deal with the issues that early-adopting Leaf drivers will face and test my tolerance for "range anxiety" -- the worries about having enough electricity to go where you need (or want) to go. Nissan says 20,000 customers have already ordered the all-electric subcompact, with deliveries due to begin next month. So there'll be lots of car owners going through a similar reality check.

The Leaf's basics
First, the basics: The Leaf is a hatchback that can seat five (we proved that on Sunday night with the neighbors) and still leave a good amount of cargo room in the back. Its styling is similar to that of the Nissan Versa, but with a swoopier tail end. The list price is $32,780, but that figure can be reduced by a federal tax credit (up to $7,500) plus state and local incentives. The car can also be leased for as little as $349 a month.

The Leaf is powered by an 80-kilowatt electric motor, and it runs totally on electricity that's drawn from a plug and stored in a 600-pound battery pack under the floor. Because the Leaf lacks a gasoline engine, it's quiet -- so quiet that Nissan has built in a faint synthetic whine that comes on when the Leaf is traveling at 18 mph or less, just to let pedestrians know the car is coming their way. At higher speeds, the noises of the tires and the motor are enough to do the trick.

This is no glorified golf cart: Even though there's no vroom-vroom sound, the Leaf offers plenty of get-up-and-go.

The common refrain you hear about the Leaf as well as the Chevy Volt, the battery-plus-gasoline-powered electric car we drove last month, is that they drive "just like a regular car." In normal mode, the Leaf does drive like a regular car, or perhaps a regular hybrid -- a verdict that was seconded by my Prius-driving neighbors. But if you want to find out what driving a not-quite-regular car feels like, you can use the Leaf's "palm shift" drive selector to toggle the drive train from normal mode to "eco-mode."

In eco-mode, the accelerator seems a bit less responsive, and the brakes grab a bit more aggressively. Those tweaks help the Leaf hold onto more of its electric power and recover more electricity from the regenerative braking system. The payoff comes in the form of a 10 percent increase in the car's range.

You can also increase your range by going without the heater on a cool, misty Seattle morning. At one point, I could fiddle with the Leaf's controls to show a variety of readings for how many miles I had left: 55 miles (normal mode with climate control), 59 miles (normal without climate control), 60 miles (eco-mode with climate control) or 65 miles (eco-mode without climate control).

Looking for a charge
I have to admit I was fixated on the routine for recharging the Leaf, since that's likely to be a key sticking point for potential buyers. Nissan says it can take as long as 20 hours to charge up the car using a standard 120-volt circuit. If you hook up to a 240-volt Level 2 charging station -- which can be installed in your home for the estimated cost of $2,200 -- you can cut that time down to eight hours for a full charge. A 480-volt Level 3 charging station can bring the Leaf's lithium-ion batteries to full power in 30 minutes or less. Once you're fully charged, you're good to go for another 100 miles or so.

Chevrolet went with a different strategy for the $41,000 Volt. Its all-battery range is lower (25 to 50 miles), but it takes just 10 hours to charge up from a 120-volt outlet, or four hours at 240 volts. And because the Volt also has a gasoline engine on board, you can go 350 miles or so before filling up again at a gasoline pump.

Because of this fundamental difference, the installation of fast-charging stations is more important for Leaf owners than for Volt owners. The federally supported EV Project aims to get 15,000 publicly available charging stations installed in six states and the District of Columbia over the next year, and thousands more will no doubt join the list.

Today, however, the pickings are slim: The number of publicly available 240-volt charging stations in the Seattle area can be counted on one hand, and I haven't yet found a place to plug in at 480 volts if need be. Because we're gearing up for an extended test drive, I wanted to make sure I could top off the batteries as much as possible. And that's what motivated my search for an outlet in the parking garage nearest to msnbc.com's headquarters.

At first, I hunted around the edges of the parking level, to no avail. Then I wandered around the stairwells and access doors -- and found my first prospect, near the door to the cafeteria. Unfortunately, the spaces surrounding that outlet were all marked for disabled parking. It wouldn't have been P.C., or legal, to park there -- even with an zero-emission car.

Finally, I came across the perfect place: An open "compact car" slot right next to an elevator lobby, with an electrical outlet just inches away. I eased my car into position, flipped open the plug-in door on the Leaf's hood, grabbed my recharging cord and let the juice flow in. Victory at 120 volts!

Every hour of recharging lets you recover about 4 miles of range, so while I've been tapping away at my computer, the Leaf has regained all the power it lost during my drive to the office.

This exercise in power-hunting made me realize that plug-in parking places will become more highly prized as more electric cars enter the market. They'll be as sought after as the electrical outlets in airport terminals. It's not too early to start reserving some of the prime parking spots for electric vehicles -- or to installing more 120/240-volt charging outlets in parking ramps and public places.

The alternative isn't pretty: In the months ahead, there just might be a lot more people like me, lurking around the garages like voltage vampires.

After charging up, I'm all set for an adventure. Keep checking our Green Innovation section for more about electric cars and our "Electric Road Trip." Don't forget that you can try out the Leaf yourself during the "Drive Electric Tour," sponsored by Nissan.

Connect with the Cosmic Log community by "liking" the log's Facebook page or following @b0yle on Twitter. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.