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My Week with the Chevy Volt

Posted: July 11, 2012 at 5:00 pm   /   by

Now for something completely different …

I’m a Conservative blogger who favors free markets, limited government, and fiscal responsibility.  And here I am writing an article about the Chevy Volt. So you might think the article will be some sort of attack piece on government bailouts, GM, the UAW, environmental extremism, wasted taxpayer money, and stuff like that, no?

Well, it isn’t.  This post is about the car, not the politics.

Full disclosure: Thanks to my daughter, an ace public relations professional whose favorite client is GM, I had the chance to test-drive a Chevy Volt for a full week.  She told me that if I chose to, I could write anything I wanted about the car.  So here goes …

Bottom line:  I like it.  I miss it — even after just one week.  It’s fun, and it’s interesting to drive. (More disclosure: I’m an engineer.)  And it does save on fuel costs as I describe below.  But the car is still pretty expensive.  The base sticker price on this vehicle is about $40,000.  With the goodies on my test unit, it’s about $43,000.  My daughter tells me that buyers are still getting a $7,500 federal tax credit (wow!), and that helps a lot.  But that credit may disappear abruptly, so I’ll disregard it for the rest of this article.

About the car —

First of all, this is not a “hybrid”.  This is a true electric car.  The only motor that turns those wheels (front-wheel drive) is an electric motor.  Period.

There is a gasoline engine in the car (the same one used in the Chevy Cruze) that starts up automatically and soundlessly when the battery reaches “zero”, but its job is to spin an electric generator that powers the electric motor that drives the wheels.  According to my dashboard display, the gas-powered electric generator would have given me a 320-mile driving range beyond “battery zero”, but I didn’t get a chance to test that.

A fully charged battery is supposed be good for about 40 miles before the gasoline engine starts up.  I only got about 36 miles, but a lot of that was done at 65-70 miles per hour.  At those speeds, the display indicated that I was running the car at less than maximum efficiency.  Based on that same indicator, if I had driven those miles at about 40-50 mph, I would have done better.  But then I would have been obstructing traffic flow, and I wasn’t curious enough to try that (!).

When the display says the battery is at “zero”, it isn’t literally at zero because there has to be enough battery energy left to get started again after the car has been turned off.  I inferred that at “battery zero” the Volt transforms to an electric car with a gas-powered electric generator sufficient to run the drive motor for normal driving plus a current-surge-assist from the battery when you really put your foot down on the accelerator.

It all works.  But I would say pick-up, for pulling onto a freeway, was only ‘adequate’ in the battery-only mode.  Pick-up seemed better when the gas engine was running, and there is an optional mode in which you can force the gas engine to run even when the battery indication is still above “zero”.  This mode is recommended by Chevy when pulling a trailer up a hill (for example).

There is some “regenerative braking” in the design, which means that when you press the brake gently, the drive motor becomes a generator and puts some energy back into the battery at the same time it slows the car.  If you have to brake fairly hard, you won’t get much energy back from this effect.  In fact, by the law of conservation of energy, you must necessarily get back less energy than the battery expended when stopping the car.  Nonetheless, regenerative braking does conserve some energy.

Initially, I had thought that with the gasoline engine running, the battery would gradually re-charge while driving around.  Some energy may indeed be pushed back into the battery, but I didn’t drive far enough to see the battery go back above “battery zero”.  Whatever is put back may be used up anyway when a current surge is needed for acceleration or hard braking.  Apparently, the only effective way to get the battery back to full charge is to plug the car into a wall socket, as intended.

So … how does one charge the battery? 

The car comes with a charging device that plugs into a standard 117 volt, 60 Hz, 15 amp circuit.  That’s the kind everybody has, and that’s what I used.  The other end of the charger cable resembles a gasoline hose spigot. It plugs into a port on the left front fender.

I have a little gizmo called a Kill-a-Watt that let me monitor the charging.  Measured power consumption was a steady 1300-1400 watts and measured current was 12-13 amps AC.  I had nothing else loading down this particular circuit.  If other appliances had been running, the charger is supposedly smart enough (by monitoring line voltage?) to lighten its demand.  That would obviously lengthen the recharge time.  Of course, your circuit breaker is always there to protect you, but I wouldn’t recommend trying to run a toaster oven on the same circuit at the same time as your Volt recharger.  I wasn’t curious enough to try that either.  Maybe next time.

During the test week, I did four full recharge cycles from “battery zero”, and the average energy to do each one was pretty close to 15.8 kilowatt-hours (kWh) every time.  At 1350 watts, that implies a recharge time of (15.8 kWh) / (1.35 kW) = 11.7 hours, and indeed it took about 12 hours for a full re-charge.  That means overnight (at least), but that’s ok by me … electric rates are lower at night.  The car has a charging status light on the top of the dashboard that I could see by just opening the house door and peeking into the garage — a nice touch.

Chevy sells an optional 220-volt charging unit that the owner can mount on the wall of the garage.  I don’t know what that unit costs, but to install a new 220 volt outlet is not very expensive (I once had an electrician put one in for $75).  If I were to buy a Volt, I’d definitely have a 220 charging unit installed in my garage.  The time for a full charge would then be about 4 hours, claims Chevy, and that sounds about right.  I’ll skip over the math, but a dedicated 220-volt 20-amp line could deliver almost 3 times the power of a 117 volt 15-amp line.  A 220-volt 30-amp line could deliver even more, but the Volt charging system may not be able to take advantage of that much power.

So where are the savings?

In my particular case, I get about 28 miles per gallon on my 2008 Toyota Avalon 6-cylinder car.  So 36 miles worth of driving takes about 36/28 = 1.3 gallons of gas on the Avalon.  Gas currently costs me about $3.60 per gallon, so that’s 1.3 * 3.60 = $4.68 worth of gasoline to go 36 miles.

The Volt gives me that same 36 miles for 15.8 kWh of electrical energy.  That’s about 2.3 miles per kWh.  By the way, this metric, miles per kWh, may be the way everyone rates car efficiency in the future as we move to electric cars.

Now, my power company charges me 5.5 cents per kWh at off-peak rates, so those 36 miles cost me 15.8 * 5.5 = 87 cents.  That’s pretty cheap.  It’s equivalent to buying gas at (0.87 / 4.68) * 3.60 = 66 cents per gallon.  I haven’t seen gasoline at that price for decades!  Stated another way, it’s equivalent to paying the current price for gasoline but getting (3.60 / 0.66) * 28 = 153 miles per gallon from my Avalon.  I never have, and I never will, see that kind of mileage from a car’s gasoline engine.

Of course these impressive numbers only apply to the first 36 miles driven, but every trip starts with those first 36 miles or some fraction thereof.  So depending how and where one drives, the savings can be substantial.

As always, YMMV (your mileage may vary) because everyone’s situation is different.  But if I were to use up my overnight charge every day for a year, I’d save up to 365 * ($4.68 – $0.87) = almost $1400 per year on gasoline. That’s a lot of saved money.

On the other hand, a new fully loaded Chevy Cruze costs about $23,000 or about $20,000 less than a Volt.  So it would take about 14 years of those savings just to break even on the cost difference between the prices of those two cars.

Then again, with a 220-volt charger, I could re-charge more than just once per day.  And if I compare the cost of a Volt to a more expensive car, the break-even would come a lot sooner.  But at today’s Volt price of $43,000, savings alone would probably not be a good reason for me to buy a Volt.  It’s close, but it’s not quite there — yet.

Of course, there is the “green” factor.  I myself am skeptical about man-made global warming.  From what I’ve read, it looks like man-made CO2 does indeed warm the atmosphere, but the big question for me is how much?  The answer appears to be:  only a little when compared to variations in water vapor, solar activity, and other natural, uncontrollable phenomena.

Anything else?

The car’s handling feels very nimble to me, and it’s easy to park.  It has a shorter turning radius than my Avalon.  The side-view mirrors are excellent — I’m picky about that.  My wife likes the look of the car — and she’s picky about that.

The hatchback model I drove has a little window at the bottom of the hatch that would allow me to see a tricycle or other short object behind the car.  I like that too.  The seats drop down nicely for cargo.  The electronics are good, although the touch-sensitive panel takes some getting used to — I prefer the tactile feel of detent buttons and switches.

Finally …

I’d have liked to drive the Volt a while longer, and maybe I’ll get another chance.  We tend to keep cars a long time in our family. I had been eyeing a Buick Lacrosse for our next new car.  But when we’re ready to buy a new car, I’ll be looking closely at the Volt.  Today’s extra cost and the doubtful environmental benefits notwithstanding, an electric car is just plain cool.  I want one.

David Leeper

David Leeper

David Leeper is a retired engineer living in Scottsdale, AZ, with his wife of 45 years. He is currently a volunteer science teacher at In his 40-year career he held positions from lab technician to technical vice president at Bell Labs, Motorola, and Intel. He holds 16 patents in telecom technology and a PhD in electrical engineering from the University of Pennsylvania. During his career, he wrote mainly for technical journals including Scientific American. He began writing for in 2011.
David Leeper

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My Week with the Chevy Volt