At first it looked like an infielder’s batting average: the number 230 flashed on signs at baseball stadiums — and in TV sports coverage — this summer. But the zero took the shape of a cartoon happy face.
In fact, the mysterious number was put there by General Motors, I learned when I visited the company’s Technical Center in Warren, Michigan, in early August.
It was a teaser: 230 is the "miles per gallon gasoline equivalent" (MPGGE) for the Chevrolet Volt, the so-called extended-range electric car GM promises to introduce by November of next year. The smiley zero represented a happy electrical socket.
GM’s marketing mavens were trying to pique curiosity about the number. It is indeed impressive compared with 20 MPG for an average car and 40 or 45 MPG for a diesel or hybrid.
“Volt is becoming very real very fast,” promised Frederick “Fritz” Henderson, the company’s CEO. He was welcoming press and the public to a special sneak peek inside the company’s design studios, labs and factories, offering reassurance to the taxpayer who had just bailed out what was once the world’s largest industrial corporation.
Barely two weeks out of bankruptcy and not quite a year after it had unveiled the production version of the Chevrolet Volt, a present to itself on its 100th birthday, GM was showing off the car’s progress.
“Our Chevrolet Volt extended-range electric vehicle will achieve unprecedented fuel economy,” Henderson said. It would not just break but shatter the 100 MPG mark.
GM explained the meaning of the mysterious number at an August 11 press conference in Warren, Michigan. Photo: Steve Fecht for General Motors
“Triple-digit efficiency” has the sound of something radically new and exciting. The number 230 is magic.
But it’s also misleading. The whole point of the Volt is that it runs on electricity alone, for 40 miles or so, before switching to a small gasoline engine that recharges its battery, which continues to drive the electric motors on the wheels. It gets about 50 MPG in that mode. So if you drive less than 40 miles, you won’t burn any gas at all.
How much electric driving and how much gasoline driving go into the 230 MPGGE calculation? GM says the number comes from an experimental scenario devised by the EPA, which is seeking MPG equivalents to allow comparison of electric- and hydrogen-powered vehicles with conventional and hybrid systems. These are new kinds of measures — a “test test,” if you will — involving a realistic mix of electric and gasoline driving. All MPG tests are to some extent arbitrary, reflecting conditions and assumptions — that’s why they say, “Your mileage may vary.” But this method is especially random.
GM wanted to be able to brag that Volt was the first car ever to earn triple-digit fuel efficiency, even though the number was not official or EPA-endorsed. The EPA, now playing on the same team as GM, released a statement saying that while it has not tested the Volt, it “does applaud GM’s commitment to designing and building the car of the future — an American-made car that will save families money, significantly reduce our dependence on foreign oil and create good-paying American jobs.”
Almost immediately, Nissan claimed that the Leaf
, the electric car whose design it had just revealed and plans for next year, also would get 367 MPG according to the same EPA equations GM was using.
But the Leaf is a wholly electric car — shouldn’t its MPG be infinite?
These numbers are among many misleading figures flying around the electric-car world. Discussion is likely to be full of such confusing figures as green technologies emerge. How can we compare hybrids with electrics, hydrogen with ethanol?
A technological naïveté, sometimes willful, sometimes wishful, surrounds the whole subject of electric cars. All too glibly, people assume an electric car is green — that is, without emissions. In fact, of course, it is only as green as the means used to make the electricity. Generating the electricity centrally has advantages of scale, but distributing it is wasteful and requires energy expenditure on infrastructure. And with coal and oil still the source of most electricity, an electric car has to be thought of not as fossil-fuel-free but simply as a car with a long tail pipe.
This was another problem with the 230 number: it didn’t account for any fuel — coal, oil, natural gas — that might have been burned to create the electricity used by the Volt.
There are many ways to measure automotive efficiency for comparisons. The simplest is cost per mile. The Volt will cost 2 cents per mile to run, based on a calculation of 10 cents per kilowatt hour, according to GM estimates. A car running wholly on gasoline at $3.50 a gallon costs about 10 cents per mile.
But the best calculation method so far, widely used in Europe and by international organizations, is grams of carbon emissions per mile or kilometer. This gets directly at the issue of global warming by tracking the amount of greenhouse gas generated.
The California Air Resources Board uses this test. According to CARB, an SUV such as the Ford Explorer emits 400 grams of carbon per mile and a Prius 200 grams. Frank Weber, chief engineer of the Volt, told me that the Volt’s number would be about 55.
Carbon per mile is an important measure for another reason: coal plants are still the largest source of electricity generated in the U.S. — and overwhelmingly the largest in China.
Carbon generation by power plants needs to be factored in to MPG equivalents, even if central generation is more efficient than dispersed generation (i.e., by the Volt engine) and even if electric generation plants can be cleaned up more efficiently than individual automobiles.
Of course, by the same token, existing electric cars can magically become greener if we shift to wind, solar or hydro to power them.
The numbers coming out of Tesla
, the Silicon Valley-based startup and media darling, are as big a problem as 230. Tesla’s founder, Elon Musk, constantly invokes Moore’s law to predict improved battery capacity. But the comparison is misleading. Moore’s law, of course, refers to the exponential growth of silicon memory capacity.
Yes, the chips in our laptops have improved by leaps and bounds — but not their batteries, which remain a source of discontent for most of us. Considering that engineers have been working on automobile batteries for nearly 125 years, and one recent sober figure suggests that battery capacity will grow at perhaps 8 percent a year, the auto battery graph is a long way from the silicon graph.
Tesla claims a range of 220 miles for its $105,000 Roadster but refuses to make cars available to the press for testing to validate these claims. It continues to get upbeat publicity and media coverage. Recently, it announced that it’s developing a 300-mile-capacity battery pack and is constantly proclaimed to be on the verge of “full production.” But when you press a company rep, as I did recently, the picture turns out to be much more modest: At the opening of Tesla’s Manhattan dealership a couple of weeks before GM’s Volt event, Colette Niazmand, senior marketing manager, told me that the company had sold 1,200 cars, of which 550 to 600 had actually been delivered.
Also problematic are the numbers of the Chinese electric car company BYD
. It claims it has developed a new kind of battery, which is calls lithium ferrous phosphate, that can run for 250 miles on just three hours of charge — and costs half as much as lithium batteries. Perhaps BYD has indeed made a breakthrough in battery capacity, but no one has been allowed to test that claim either, and it is repeated by credulous media, usually with the justification that the assertion was good enough for Warren Buffett, who invested $230 million in the company.
That 230 again — GM didn’t need it to make the Volt attractive. Running 40 miles on electricity and 50 MPG on gasoline is a respectable start for the reborn company. GM has plenty to be proud of even if the Volt, at a likely price of about $40,000 with production of some 70,000 cars a year, doesn’t change the world.
More than a glib number, what made me feel positive about the Volt was seeing real cars being built in the preproduction plant in Warren. The factory floor was covered with cars in various states of completion. Two Volts a day are being finished as part of the preproduction shakedown of manufacturing methods; full production and sales are scheduled for November 2010. Whether the Volt, no beauty, will sell, much less become as fashionable as the homely Prius or other hybrids remains a question.
GM made a better sales pitch when it rolled out the Volt with the slogan “You may never buy gasoline again.” This line, frequently repeated by GM’s Bob Lutz, turns on another number, the much quoted stat that 80 per cent of people in the U.S. commute less than 20 miles each way, making the Volt’s 40-mile range practical for daily life. The gasoline engine is left to power you to Thanksgiving at Grandma’s.
Of course, the electric car is only part of the picture: GM has neglected consideration of charging infrastructure. Many electric-car schemes depict charging as a simple matter: just plug in your car in the garage overnight. But many people don’t have a garage. They park in common lots or on the street when they’re home — and they are not home every night.
At the Volt preview in Warren, Fritz Henderson was asked about how owners of Volts without garages were to charge them. “If you’re going to park it on the street,” he admitted, “I don’t know how to address that situation.”
(At least Nissan acknowledges the problem. For its all-electric Leaf car, the company is working with Shai Agassi’s Better Place
program, which enlists governments and business to install recharging equipment.)
Companies will have to cooperate on recharging. Ultimately, the number that may matter most in making electric cars practical is J1772
That number is the designation of the draft standard for a universally agreed on plug being prepared by the Society of Automobile Engineers. They’re the folks who do the dull but important work of promulgating standards for such things as grades of transmission fluid and threads on spark plugs. A plug-in system as universal as, say, USB ports, might be a happy-face socket indeed.