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Chevy Volt Released: Efficiency & the Big Question

Steve Puma | Thursday January 27th, 2011 | 0 Comments

2011 Chevrolet Volt on the Road © 2010 General Motors and Wieck Media Services, Inc.There is no question that General Motors has a lot riding on the 2011 Chevrolet Volt: it is the first new vehicle model to be delivered (on GM’s 100th anniversary), since the company filed for Chapter 11 reorganization in 2009, with significant help from U.S. taxpayers. Not only is the Volt a huge opportunity for “New GM” to prove that American automakers are still relevant, it is also an opportunity for the company to make good on its promises to deliver competitive alternative-fuel vehicles. In the latter department, GM will have its work cut out for it: Toyota’s Prius is way out in front, Nissan’s Leaf appears to be an excellent product, Ford has announced an all-electric Focus, and numerous others will soon to be available.

So, it was no surprise that the San Francisco stop on the Volt’s cross-country press blitz was held at the amazing Cavallo Point Lodge and included a 100-mile test drive through some of the most gorgeous scenery that the Bay Area has to offer (nothing like a spectacular view of the Golden Gate bridge, or lunch at Nick’s Cove, to generate some good will). Fortunately for General Motors, the Volt makes an excellent impression all by itself. I don’t think that anyone was more surprised that yours truly. Although there are some lingering questions, the Volt is a solid car and should prove to be a worthy addition to the growing list of EV offerings.

The “G” stands for “green”, right?
First Pre-Production Chevy Volt Rolls Off The Assembly Line (Photo by John F. Martin for Chevrolet)GM believes the Volt is so intriguing that it will have Americans rushing into dealerships to check it out. The GM spokesperson pointed out that having the Volt on the menu means that the company will also sell more of its other offerings, simply because not all buyers have the same needs or budget. The company’s sales and cost projections show that there will likely not be any profit made on the first-generation Volt. Indeed, GM representatives freely admit that almost all of the (first-generation) Volt’s benefit will come in the form of good will towards the company and its future products, which it claims will include a second-gen Volt and other “green” vehicles.

GM notes that increasing the number of low-emission vehicles it offers is a permanent part of its long-term strategy. GM representatives I spoke with were unanimous in their agreement that the Volt will not be a repeat of the EV-1 debacle. A commonly cited example was the recent green-lighting of a, Cadillac-SRX-based, plug-in hybrid, by GM’s CEO, Daniel Akerson. In any case, it is simply not logical to think that GM would produce any more than 10-20 thousand Volts per year, for the next few years. Most sources agree that consumer demand isn’t there quite yet, especially when you consider that all current hybrid and electric vehicles come at a price premium over their gasoline-powered cousins. For the next several years, most EVs and hybrids will be purchased by the small, but influential, segment of the market known as “early adopters.”

In Part Two, I’ll tell you about my test drive impressions, but for now, I’m going to skip right to the two points that I think are most salient: the Volt’s true fuel/energy efficiency, and what I’m going to call The Big Question: “does the Volt’s gasoline engine power the wheels, directly, and does it even matter?”

Your Mileage Will Vary
2011 Chevrolet Volt at a Public Charging Station  © 2010 General Motors and Wieck Media Services, Inc.While the Volt can deliver some very high fuel efficiency, actual mileage is extremely variable, and heavily dependent on individual driving style, something that is sure to drive potential buyers batty, at least for now. This quote from Edmunds online review explains the situation: “Suppose you have a 20-mile round-trip commute, and you plug in your Volt every night when you get home…Congratulations! Your fuel economy is [theoretically] infinity, because you’ll never run the battery pack down all the way. But if you have a 100-mile commute, you’ll be driving at least 60 miles a day under gasoline power, so you’ll have to refuel on a regular basis. And, in an Edmunds fuel economy test of a Volt with its battery depleted, the car returned only 31.4 mpg, in mixed driving. That’s far below the typical fuel economy provided by regular hybrid vehicles.” Car and Driver also was quick to highlight the low fuel economy of the Volt, when running in battery-depleted mode.

However, both Edmunds and Car and Driver fail to point out that 75% of U.S. drivers drive less than 40 miles per day, which means that the higher-, or infinite-, mileage scenarios are much more likely to be the norm. In addition, it is also highly likely that Volt owners with the proper access to electrical outlets (especially those individuals with very long commutes) will seek to obtain at least a partial charge for their vehicles while at work.

Other anecdotal evidence shows promising results. A Motor Trend editor claimed a 127 mpg average, driving the Volt over various typical Los Angeles driving scenarios. In an attempt to be as fuel-inneficient as possible, a different Motor Trend editor claimed a low average of 75 mpg. As Motor Trend goes on to conclude, even at the low end of the spectrum, the Volt is still incredibly fuel efficient.

The Big Question or Much Ado about Nothing
2011 Chevrolet Volt Interior Showing Front Seats and Instruments © 2010 General Motors and Wieck Media Services, Inc.It seemed that GM had done everything right, at least from a public relations perspective. The Volt was receiving accolades as the first mass-market, extended-range electric vehicle. GM claimed the Volt was a “true” EV, because the small gasoline motor only ran a generator to charge the batteries; it did not actually drive the wheels, at least not directly. Then came the big news: GM flip-flopped on its initial statements, just a little: “under certain condition” the gasoline engine does, in fact, connect to the drive train, and assist the electric motor in driving the wheels. The firestorm of bad press that ensued was gigantic: many felt betrayed or lied to, and were sure that this was a red flag indicating business-as-usual at General Motors.

The confusion lay in GM’s use of vague engineering- or marketing-speak to describe the Volt’s drivetrain, using terms like “all-electrically driven vehicle” or “no compromises” or that “”The Chevrolet Volt is not a hybrid. It is a one-of-a-kind, all-electrically driven vehicle designed and engineered to operate in all climates” or that there is “no direct mechanical linkage from the engine, through the drive unit to the wheels.”

The truth, once explained, actually sounds pretty simple. The gas engine drives a generator, which when the batteries are depleted, creates electricity that goes to the batteries, powering the electric motor, which drives the wheels. While battery power still exists, only the electric motor is running.

Edmunds Inside Line explained it this way: “As in the Prius, the Volt’s drivetrain includes a planetary gear set that acts as a transmission. The intricacies of planetary gears are many, but in rough terms each element (electric engines and internal combustion engine) of the Prius or Volt drivetrains are hooked up to different elements of the gear set. In the Volt, its Ecotec engine is clutched to the outer ring gear and as the car’s speed reaches the edge of efficiency for the electric motor, that ring is set from its normally rigid mounting in the 4ET50′s case and allowed to spin. That has the Ecotec driving the front wheels.”

2011 Chevrolet Volt © 2010 General Motors and Wieck Media Services, Inc.While it is true that the Volt can connect the combustion engine to the transmission, it is not possible for the gas engine to drive the Volt, alone, without the motor. There is, actually, only one scenario under which the gas engine will be connected directly to the drivetrain: when the batteries are depleted and the car is traveling at speeds over 70 mph. According to GM engineers, this only happens because it actually improves the Volt’s efficiency.

It is not exactly clear why GM initially chose to obscure the truth about the Volt drivetrain. However, now explained, the real impact appears to be relatively inconsequential, good or bad. (The only damage appears to have been to GM’s image.)

Fin
So far, so good. Based on my discussions with GM employees, and my own impressions of the car itself, I think that the Volt will deliver well on its promises. Most owners should experience excellent fuel economy, and the PR issues seem to be to little more than poor communications. In Part Two, I’ll talk about what it feels like to actually drive the Volt, and what I feel the pros and cons are, for an average driver.

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Steve Puma is Director of Business Development for SABA Motors, and a sustainability writer/consultant. His work focuses (mostly) on clean transportation, including Plug-In Electric Vehicles, something he is very passionate about.

Steve holds an MBA in Sustainable Management from Presidio Graduate School and a BA in Computer Science from Rutgers University. You can learn more about Steve by reading his blog, or following his tweets.


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