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Why is the 2011 Chevrolet Volt NOT a Hybrid?

 
20 4,119 views August 20, 2009

first pre production chevrolet volt prototype 001

first pre production chevrolet volt prototype 001

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Even after 10 years, hybrid-electric vehicles are still foreign to large parts of the car-buying public. People aren't sure if they're worth the money, they worry that the battery may need replacing, and some still don't understand that you don't need to plug in a hybrid.

Well, brace yourselves. Things are going to get vastly more complicated. And one cause of confusion is the difference between a "plug-in hybrid" and cars like the 2011 Chevrolet Volt, which plugs in and has both a battery pack and a gasoline engine.

Hybrid: mostly gasoline powered

As we commonly use the term "hybrid," it refers to a car with a combustion engine that derives some part of its motive power from electricity. In cars like the 2010 Toyota Prius, that energy is recaptured via regenerative braking.

In the future plug-in version of the Prius, some of that energy will also come from plugging the car into the electric grid. So, if you can plug it in, it becomes a "plug-in hybrid," or PHEV. That may give it 10 or 12 miles of electric range, but only under a limited range of circumstances (low speeds, light loads, warmed-up engine).

The 2011 Chevrolet Volt, on the other hand, is an electric vehicle, pure and simple. It's an EV with a very short range on battery power, mind you: just 40 miles. But for those 40 miles,  it runs exclusively on battery power as an electric car.

Volt: electrically powered, always

After that, the gasoline engine in its Voltec drivetrain switches on, but it doesn't power the wheels. The only way the Volt can move along the road is using the electric motor that turns the front wheels.

The gas engine? It simply runs a generator that recharges the battery enough to keep the Volt moving for another 250-plus miles. Its function is not to move the car, but to extend the distance the battery pack can take it. Hence, the engine is a "range extender".

In Volts that travel less than 40 miles a day and are plugged in daily, the engines may not get switched on for weeks, if ever. That's why we call the Volt an "extended-range electric vehicle," or EREV.

Delete parts; what's left?

Or, we can put it another way: The Volt is an EV. Take out the gasoline engine, and it runs as an EV. But the Prius is gasoline-powered (with or without the ability to plug in). Take out the battery pack and electric motors, and it still runs as a gasoline car.

Yes, yes, we know "hybrid" means a combination of different power sources. But it's important to understand the crucial difference between what we call hybrids today (e.g. Prius) and the plug-in electric cars of tomorrow, with or without range extenders.

Initial testing of Toyota’s plug-in hybrid system installed in the second-gen Prius has returned fuel-economy figures of 65mpg

Initial testing of Toyota’s plug-in hybrid system installed in the second-gen Prius has returned fuel-economy figures of 65mpg

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Comments (20)

  1. By  Phil Colley with GM Posted: 8/21/2009 12:28am PDT

    Great story. Get ready for the series hybrid backlash ;-)
     
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  2. By Nic Posted: 8/21/2009 5:28am PDT

    Hum... I disagree with with because you are omitting something important: people drive more than 40 miles a day. And so the Volt still uses gasoline on a daily basis! A car that uses gas is NOT an EV. You should have talked about a real EV (i.e. without any ICE engine) like the Nissan Leaf, that can achieve 100 miles on batteries. Unless you were asked to talk about the Volt...
     
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  3. By Deb Posted: 8/21/2009 5:51am PDT

    Not all people drive more than 40 miles a day. This is perfect as I drive less than 10 miles a dday on a regular basis, but if I forget to plug it in or want to drive to my Sister-in-law,s in Mass. I don't have tp worry that I'll run out of power. It is an EV, for sure!
     
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  4. By JDT Posted: 8/21/2009 6:20am PDT

    A battery & motor is a BEV (battery electric vehicle). An engine & motor, HEV (hybrid electric vehicle). Hydraulic hybrids also exist. With grid charging, PHEV (plug in hybrid electric vehicle). There are series & parallel HEVs & PHEVs. The Prius is parallel, both the engine & motor propel. The Volt is a series HEV. The engine makes electricity & powers the motor. Series HEVs have been commercial for over a decade. The Orion/BAE buses in NYC are such.
     
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  5. By  Luke Posted: 8/21/2009 6:26am PDT

    Yeah regardless of how many miles people drive, the main distinction to be drawn here is that the Volt is propelled via its electric motor, whereas the Prius (so far) is propelled by an ICE which gets help from a battery pack. Prius can function without the electricity, the Volt cannot. I understand your bone to pick in calling the Volt a true EV, but it's really an EV with a range extender ICE on it whereas the Prius is kinda the opposite.
     
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  6. john_v avatar John Voelcker Posted: 8/21/2009 6:53am PDT

    @JDT: I considered adding in the series/parallel distinction, which is the technically accurate way to explain it all.
    But I think those terms are far too esoteric for the general car-buying public. As it is, I think there will be confusion between "hybrid" and "electric" ... hence the piece.
     
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  7. By Sharon Posted: 8/21/2009 6:54am PDT

    It is time for America to give up foreign cars and only drive American EVs! We need to give up our dependence on foreign oil and on foreign vehicles!
     
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  8. By  Phil Colley with GM Posted: 8/21/2009 7:13am PDT

    @JDT @JohnVoelcker But it only functions as a series hybrid when the battery is depleted, so we agree with John, EV. For the first 40 pure electric miles, the battery provides full power without support from the engine generator.
     
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  9. By Tony Posted: 8/21/2009 7:32am PDT

    They should do a test run as in getting some volunteers to test drive it for a year. As I live in the city, and work less than 5 miles away, the only time I'd use gas is probably trying to make it to a distant tennis match! ME! ME! ME! I wanna be the first to put my name in the hat! Here u can use my hat too! (Smile)
     
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  10. By JJ Posted: 8/21/2009 8:26am PDT

    I think something that cements this as an EV in my mind is that you can replace the ICE with any number of other Range extenders in the future and leave most of the vehicle's design untouched. Should H2 become a viable source of extended electricity storage through fuel cells, then that could be swapped in. With the current Hybrids out there this is not the case.
     
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  11. By unni Posted: 8/21/2009 12:14pm PDT

    " The gas engine? It simply runs a generator that recharges the battery enough to keep the Volt moving for another 250-plus miles " - Wrong - as i herd Volt generator does not recharge battery all time ( as i herd it does not recharge at all - )
    It directly powers the electric motor. Even GM say it never powers battery at all - i still think it may power battery some time :-)
     
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  12. By John Posted: 8/21/2009 12:53pm PDT

    The problem with the EV is at the end of the 250 miles your dead in the water and can go no further where the hybrid can run indefinately with only momentary re-fuel stops. How long does it take to fully recharge the volt batteries once their charge is depleted?
     
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  13. john_v avatar John Voelcker Posted: 8/21/2009 4:40pm PDT

    @John: You can add more gasoline and go another 250-plus miles.
     
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  14. By  Phil Colley with GM Posted: 8/22/2009 10:37am PDT

    @unni You're right the engine generator doesn't recharge the battery, but it sustains the battery charge so the battery can help provide peak performance when it's required - such as driving up a steep incline or for high-speed maneuvers. Not sure where the "even GM says it never powers the battery at all" because that's not true since it sustains the battery's charge when the battery is depleted.
     
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  15. By Dave Brusiee Posted: 8/23/2009 11:10am PDT

    I don't believe that the battery gets recharged at all after 40 miles. The electricity generated by the gas engine and generator will be used to run the DC motor to power the vehicle. It would be extremely inefficient to partially charge the battery and then immediatley draw it out. /DaveB
     
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  16. By Rich Posted: 8/25/2009 3:54pm PDT

    To all posters asking about the generator and battery combo and how it works, ask Lyle Dennis over at GM-Volt.com. He can tell you everything about the vehicle. It's surprising that people still don't understand how this setup works, GM needs to work on clarifying it to the public before its release.
     
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  17. By Mike Posted: 8/28/2009 3:51pm PDT

    Ok... Why are we not puting altanators (sorry for all misspellings)on these cars to recharge them while driveing??? Is chevy just stupid??? Or is it the oil companys fault??? But people the point is not that it uses gasoline the point is this is the first step that were taking to help the planet. Soon were guna run out of gas... We need electric cars now so we can keep our presious suply of gasoline for better things. All gas cars should be purchased and disposed of melted down and added to the steel suply...
     
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  18. By  honeypot Posted: 8/30/2009 1:16am PDT

    all I want to know is, WTF took so long?
    I know you guys could have done better than this in the 70's!
     
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  19. By John Posted: 9/10/2009 9:17pm PDT

    @Mike #17 post:
    I highly recommend that you refrain from making a bunch of off based comments like "why are we not putting alternators on these cars" and "Is Chevy Stupid". Do a little research before making comments. In this case Chevy and GM are not "stupid", you are.
    An alternator is essentially a small generator that is driven by mechanical means. Now there are some technical differences, however they are close enough to call them the same. Huh, didn't GM put one of those in the Volt? (Yes)
    The Volt will use energy from the batteries to power the vehicle and when the batteries are low the engine driving a generator will then take over not only to move the car forward but to also power the car.
    Couple of other thoughts...
    1. I don't know what Kool-Aid you have been drinking but we are not going to run out of gas anytime soon.
    2. Learn how to spell. You sound completely uneducated and any valid point you may be trying to make gets discredited because of the way you spell.
    3. You should run for President or better yet, Speaker of the House. Government Health Care and melting down ALL gas powered cars are great ideas. While you are at it why don't you raise income taxes and put inflation right where it needs to be... in the double digits. We, as a society, won't all be driving EVs for the next 15 years!
    Finally, I applaud GM and the efforts on this endeavor.
     
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  20. By K.Sivasankaram Posted: 5/21/2010 10:30am PDT

    The description is just a jugglery of words. After 40 miles of pure EV operation the engine runs a generator which supplies power to wheels as well as to the battery. Thus it may be called Electric-gas-electric vehicle not a pure EV. This also must be using regenerative braking to improve mileage as does Prius. Only appreciable difference is that it uses Lithium-ion batteries instead if Ni-MH batteries. The mileage claims for Volt by the manufacturer reminds me of a auto buff who claimed more mileage by adding more batteries to his Prius than what the manufacturer indicated. This kind of fooling around goes on for ever.
     
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