• Oct 11th 2010 at 10:00AM
  • 264
On the first day of its Chevy Volt media drive program, GM officials confirmed speculation that the Volt's 1.4-liter gas engine does help drive the wheels of the car, "in low torque situations," according to Volt chief engineer Andrew Farah. "It's all about efficiency," he said. GM is using a version of its two-mode hybrid transmission that allows for a so-called "power split" mode that connects the crankshaft of the gas engine to the Volt's two electric drive motors by means of a planetary gearset. This allows the power from the gas engine to be blended with the power from both electric drive motors, primarily during high-speed operation, where GM says this mode provides 10-15 percent better fuel economy.

Leaf The Volt transaxle is more complex than many media and onlookers had been led to believe. It employs two electric motors, a planetary gear set, and three clutches, and can operate in four distinct drive modes, switching between them as conditions warrant.

The first mode is the easiest to understand, as it uses the 111 kw traction motors to drive the wheels, with all the electric power coming from the battery. This EV mode delivers 273 lb-ft of torque to the wheels and makes the Volt fairly quick to accelerate from a standing start.

The second EV mode employs both electric motors -- the traction motor and the 55 kw generator – to drive the wheels, with electric power coming from the battery. This mode blends the power by means of the planetary gearset to allow for improved highway efficiency, as both motors are able to run closer to their optimal efficiency.

The third mode happens during extended range driving, when the gasoline engine is operating. In this mode the traction motor drives the wheels, with electricity coming from the battery as well as the motor generator, which is being spun by the gas engine. GM calls this a "weak series" arrangement, as the battery is always the lead power source.
Did GM lie about the Volt?
Yes, it's not a pure EV if the engine can power the wheels. 1494 (39.3%)
No, it's still fundamentally an electric vehicle. 524 (13.8%)
I don't care as long as GM engineers used the most efficient design. 1779 (46.9%)


It's the final mode that's come as a bit of a surprise, because it is in this extended range mode where both electric motors and the gasoline engine get connected to drive the wheels. However, GM is still maintaining its stance that there is "no direct mechanical linkage from the engine to the wheels," while explaining that "the Volt is always propelled with electric power delivered by the traction motor."

While there is still likely a semantic argument to be waged here -- whether we call it a plug-in hybrid or an extended-range electric vehicle is a discussion for another day -- the bottom line is that the Volt employs a sophisticated transmission to eke out every efficiency from its drive system.

Watch Bradley take the 2011 Chevy Volt for a spin at GM's secret proving grounds.


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  • 264 Comments
      michael
      • 7 Months Ago
      Somebody finnally figured out that at 4000,00 a car nobody here in the USA could afford to buy the car except the police families and the politicians...at about 175000.00 dollars a year pension each...Evereybody else will just have to walk or ride a bike......Now had the CEO had been using his bran he could have mass produced the 3 cylinder GEO Metro even if he had built 500000 of them even if they had full frames 2x4 tube steel with a fiberglass body on them and they were real wheel drive...simple constuction..sedan delivery,, convertable or truckster body all on the same running gear and frame..and all for about 10000.00 he would have sold every one of them...45-50 miles per gallon and would go 75 mph all day long...Believe me thats the way that the CEO should be thinking,,,and that is what GM should be doing...
      mymedicalcd
      • 7 Months Ago
      ANOTHER OBUMMA MOVE TO GET RID OF DRILLING CANIDIAN PIPELINE ANY THING HE DOES HURTS AMERICA HIM TAKLING OVER GM AND HURTING STOCK HOLDERS PRETENDING TO SAY DEBT PAID GIVING WAY TOO MUCH TO UNIONS TO HELP HIS ELECTION REMEMBER HE IS A COMUN ITY ORGINIZER ANTHER WORDS SHAKEDOWN ARTIST
      • 7 Months Ago
      Wait a minute....I didn't even know it HAD a gas engine. It runs out of juice that quickly and it has a 1.4 liter, 4-cylinder gasoline engine in it? WTF is the engine FOR? Ballast? Sounds like a poorly executed hybrid to me. For a premium price, too. Just another crappy white guilt car for rich liberals to buy so they can salve their conscience.
        hugozoon
        • 7 Months Ago
        It is like a train most trains use a diesel motor to power a generator wich produces electric for the engine. The volt differs in that it also has a battery so it can go up to 60 miles with no gas!
          marcanagnos
          • 7 Months Ago
          @hugozoon
          No, this is basically a Pruis with a different design. This is not an "electric" car at all. They do have a connection with the engine to the wheels. Just because they connect through the electric motor shaft doesn't mean it's electric. MARC
          idgascreamer
          • 7 Months Ago
          @hugozoon
          I too one on a test drive ... what a piece of crap !
      michael
      • 7 Months Ago
      2 cylkinder snyder has a better idea snyder st600-c the better way to go 70 mpg max speed 65 perfect city car with good heater...3 wheeler... also real good in the far out back country areas where the max speed is 50 mph...
      • 3 Years Ago
      Volt, fantastic! Ahhh, but have you seen the hydrogen car of the future? Runs on water, produces water not smog, either driver in the front can drive it, (stearing switches to either right or left from the middle), and instead of a wheel, it has something like joy sticks for control, (no pedals). It also has interchangeable bodies that take about 30 minutes to switch out, so if you need a pickup instead of a sedan, wallah. Way cool!
        danwat1234
        • 7 Months Ago
        Hydrogen car's aren't very viable because it takes a lot of energy in order to make hydrogen from water. Besides, hydrogen car are actually electric cars with fuel cells to convert the hydrogen back to electricity. You might as well stick with pure electric cars and rang-extended vehicles so the efficiency stays high.
        • 7 Months Ago
        no it runs on hydrogen and makes water, 1 reason were not looking into hydrogen cars at the moment is it take 3 time the ratio of gas vs hydrogen to drive the same distance we need a breakthrough in hydrogen teck to put it to good use.
          • 7 Months Ago
          ...And if something goes wrong you need to run far and fast.
      Marc
      • 4 Years Ago
      It was only a matter of time before GM leapfrogged the competition and introduced the Volt. In a larger sense the American automobile industry is on a roll, despite negative press and road blocks from the DOT. Interestingly the foreign market demonstrating the most interest in the Volt is Japan, however, MITI will make it very difficult for Japanese consumers to purchase a Volt, (or any other import). For GM to gain market share in the US it must grab share in Japan. The key to success for GM, and Ford, Chrysler and domestic Truck manufacturers is to take share in Japan. This would allow increased production resulting in lower costs and more money for R&D. We may consider an import tarriff increase (not as much as Japan charges on imports), but enough to get MITIs attention to relax auto import restrictions to Japan. The Japanese consumer is changing, it is no longer considered bad taste to buy an American or European automobile. They should have the same rights as American consumers. The cult car for Japanese youth today is Cheverolet, (and not the Volt). Now, does that tell you something.
      • 4 Years Ago
      The article says it over and over: complex drive train. That means one and only one thing to me: The d**** thing is going to break...repeatedly...and it'll be EXPENSIVE to repair it. 1/2 the point of an electric vehicle is reliability. So much for that. Still looking for a main stream electric.
      Kyle
      • 4 Years Ago
      support the people that are paying the bills, buy a honda. Good milage cheap price, and if china goes under, who's going to bail us out.
      • 7 Months Ago
      I'm just wondering about how often the batterise would need to be replaced,the life of the batteries and the cost..Another question is wheh I plug this car at my house at theend of the day ,how much electic will it use at how much money..Another question iswarrantty coverage
      • 7 Months Ago
      don't see to many on the road,guess it may be the high price tag ,also the fuel stations need to be upgraded to charge these vehicles haven't seen that either...
      roleal2003
      • 7 Months Ago
      I WANT TO TELL ALL YOU TWO FACED BACK STABBING AMERICANS THAT BUY FOREIGN AUOTMOBILES TO GO TO HELL.
      lawsont808
      • 7 Months Ago
      Rear engine Chevette, or are you thinking of Corvair?
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