EV World publisher Bill Moore with Chevy Cruze equipped with Voltec electric drive.
EV World publisher Bill Moore with Chevy Cruze engineering 'mule' equipped with Voltec extended range electric drive system.

Driving the Volt 'Mule'

I get to cruise in a Chevy 'Cruze' equipped with GM's Voltec electric drive system.

By Bill Moore

"Bill... how'd you like to come to Detroit and drive the Volt?" Robert Peterson asked me in an email a couple weeks ago.

"Is it the Volt or the 'mule'," I replied, as if it really made any difference.

"It's the mule," he responded from his Blackberry.

"I was hoping it was the Volt, but okay, count me in," I answered.

Rob would, of course, tease me later about my verbal snobbery, which I deserved. But also in my defense, I was hoping -- for their sake, as much as mine -- that they'd finally mated the Voltec extended-range electric drive system to the Volt body. They hadn't just yet, but assured us all that they are within days of doing it.

Now, before I go too far with this narrative, I need to explain what I mean by a "mule." It is an automotive engineering term for a test vehicle that is used for engineering purposes as a surrogate for the production vehicle. In the case of the the Chevy Volt, the "mule" is the soon-to-launch Chevy Cruze, which is very similar in size to the Volt. While final engineering of the Volt continues apace, GM drive train engineers needed a vehicle platform to run on the road and the Cruze got the job. That's the vehicle you see in the photo above.

Because my flight back home wasn't until 7:30 PM, I was scheduled for the 4 pm drive slot, along with John McElroy of Autoline. John would get the first crack at the car, I'd get the second. The plan was to video record my drive, but the spare battery I'd planned to bring with me got left home in a last minute travel bag exchange. Fortunately, GM equipped the car with a "lipstick" camera and DVCam recorder deck. When my drive was over, they gave me a copy of the tape that I need to get converted into a format I can edit on my iMac, so that part of the story will have to wait.

A Quick Spin on Hydrogen

In the interim between touring the new Global Battery Lab, lunch with Volt program engineers and driving the "mule," GM also arranged for several of us to drive the Chevy Equinox fuel cell SUV, an event that oddly enough, wasn't a memorable as the Volt. Not to downplay the vehicle -- it is wonderful -- but with the shift of focus to PHEVs, fuel cell cars like the Equinox seem to have lost a bit of their luster, at least in my mind, which I find odd. It is, after all, at its heart and core, an electric car, and it runs great. I recall a few years back the compressor whine that made GM's early HydroGen series fuel cell cars stand out -- and not in a good way -- from Toyota's or Honda's hydrogen cars. All that is gone now.

The car manifests none of the traits of its predecessors. Sitting there in front of the GM battery lab on the Warren Tech Center campus, the car doesn't appear even to be running, but it is. You climb in, snap on the seat belt, shift the car into drive and away you go. Of course, it's not quite as simple as that if you're doing a cold start. The car does require a few seconds to wake up the fuel cell and run some computer diagnostics, a phenomenon, we would learn, found in the Voltec drive system.

What we discovered is that we are, in effect, driving a hydrogen-powered (or IC genset-powered) laptop computer on wheels, one that, like any laptop or desktop computer, has to go through a software boot-up process.

As I took my turns around the R&D center grounds, I learned from Mark Vann, the fuel cell Equinox program manager, that people taking part in the Project Driveway initiative are falling in love with the car. They don't want to give them back and they want to when they can own one. The program, began in 2008, gives the fuel cell-powered, small SUVs to consumers to drive for several weeks at no charge. The only real stipulation is you have to live near where a hydrogen fuel cell station(s) is located, and those are few and far between, being located mainly in California, just outside Washington DC and New York.

That these privileged-few test drivers become so attached to their cars, I can certainly appreciate after my brief drive. EV1 drivers felt the same way. The 100 Equinoxes taking part in Project Driveway have now amassed 750,000 miles of operation.

Saddling Up the "Mule"

After a mid-afternoon run to Starbucks across from the Tech Center for coffee (a venti-sized caramel frappuccino, in my case), we drove back to GM's fleet garage and got our introduction to the Voltec drive system by Frank Weber. Then I was paired with McElroy and Tony Posawatz to take the gray-blue Voltec Cruze "mule," with John first to drive the car.

John is a skilled driver, as well as automotive journalist, so his first inclination was to see how fast the car could go on the short stretches of street that crisscross the Tech Center. He'd gun the car, braking only at the last minute, whip it around the corner and do it again. I sat in the back seat with the DVCam recorder deck. All the time, Tony Posawatz talked about the subtle engineering refinements that still need to be made to the drive so it can handle the infinite variety of driving conditions to which millions of motorists -- we all hope -- will someday subject the car.

Finally, my turn came. The first surprise was Tony's explanation that from a cold start, the Voltec drive system in the 'mule' takes about 20 seconds to boot up as it preps the battery, turns on the computers and runs a series of software diagnostics.

What was the old joke about Microsoft designing a car? Welcome to the future of "Intel Inside." Actually, I don't know whose computer processors GM is using, but my earlier comment about driving a laptop isn't far off the mark. Posawatz thinks some time can be shaved off the start-up, especially by pre-starting the car as you walk up to it with a secure, wireless key fob or having OnStar start it for you at a predetermined time.

Because the car is, first and foremost, an electric car, starting it doesn't mean turning on the 1.4 liter, 4 cylinder gasoline engine generator. Parking garages won't suddenly be filled with noxious blue-gray hydrocarbon fogs as dozens of Volts power up at 5 pm every evening. The car will wake up, run its diagnostics and then quietly sit there waiting for you to unlock the door, buckle up and drive away.

Apart from the surprise about the boot-up time, the next revolution was how incredibly quiet the car is, not just in terms of decibels, but also in terms of vibrations. I pulled up to my first stop sign and marveled at the stillness of the experience. You'd swear the car is turned off and parked. It doesn't make a peep or even hint that its running, which I suppose will be a bit disconcerting for first time EV drivers. Certainly, most hybrids manifest the same eerie sensation when the engine turns off and the car goes into EV-mode, but this is somehow different in a hard to define way.

Launch and acceleration are totally seamless. The one-speed gearbox insures that the car goes from zero-to-whatever with a smoothness you have to experience to appreciate. In my case, 'whatever' was 60 mph in 11 seconds on my second self-timed run, and closer to nine on my first run. GM's Posawatz, who is the Volt vehicle program line manager, explained that the two mules available for the press drive were detuned to keep hot-shot reporters from smoking the tires. Target acceleration from zero-to-60 (100km/hr) is 8.6 seconds, nearly the same as the EV1.

Up and down, around and around, I went for 10-15 minutes, never leaving the Tech Center grounds, but it was enough to give me a sense of what the Volt will be like when it comes out. This is going to be as different an experience for the average motorist as moving from a non-hybrid to a hybrid is. Say what you will about GM's intent or shaky financial footing, on the engineering side, they have developed one helluva fine electric car.

And mark my words, this is an electric car. It is not a hybrid. For all our racing around, stomping on the accelerator, slamming on the brakes, whipping around corners, we could not get the IC engine to so much as burp. We zipped along at 40-50 mph in all-electric mode. It was awesome. Sure I would like to have seen how smooth the transition is between electric and extended range driving mode, but it just didn't happen; though according to Posawatz, it too is virtually seamless. I'll take his word for it.

Just in case, someone reading this isn't all that familiar with the theory behind the Voltec drive system, it works like this: the first 40 miles or so, the car operates as an electric car fully capable of running at highway speeds. At 40 miles, the onboard generator -- powered by the flex-fuel IC engine -- turns on, running at predefined RPM settings designed for maximum fuel efficiency and low emissions, and supplies enough electric power to run the car for as long as there's fuel in the tank, somewhere around 300-400 miles. GM says "several" hundred. The generator does not recharge the battery. Instead, you do that when you get home or from a public charging station using low-cost electric power, which is cheaper than using petroleum or ethanol blends. If you pay 10¢ a kilowatt hour for your electricity at home, your first 40 miles of travel will cost you 80¢ or about 2¢ a mile compared to 7.5¢ for gasoline at $3/gal. The 16kWh battery pack in the car is designed to last the life of the vehicle. Owning a Volt and recharging it at night will be roughly equivalent to adding both a refrigerator and freezer to your electric power bill, or about 80-90¢ a day.

The next milestone for the Volt program is to mate the Volt body to the drivetrain and chassis, which should happen yet this month. GM then plans to build about 100 of these preproduction prototype for testing, crashing and media demonstration purposes.

When that happens, I will be sure to have a fresh, spare battery in my Sony HD video camera.

Times Article Viewed: 12595
Published: 17-Jun-2009


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