Drove the VOLT... feels like any other car...
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From: Okemos, MI
Re: Drove the VOLT... feels like any other car...
I haven't seen anything that indicates what portion of the work the engine would be doing at 70mph. Where are you getting that?
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Joined: Feb 2002
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Re: Drove the VOLT... feels like any other car...
My understanding is that when in all electric mode, the engine doesn't contribute at all, even past 70mph. Its only when in extended mode that the engine engages the secondary motor to directly drive the car and its not just above 70mph, it can be any speed over 40mph depending on circumstances. But again, when in the initial electric only portion the engine never engages.
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Joined: Aug 2002
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From: Indianapolis, IN
Re: Drove the VOLT... feels like any other car...
My understanding is that when in all electric mode, the engine doesn't contribute at all, even past 70mph. Its only when in extended mode that the engine engages the secondary motor to directly drive the car and its not just above 70mph, it can be any speed over 40mph depending on circumstances. But again, when in the initial electric only portion the engine never engages.
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From: TX Med Ctr
Re: Drove the VOLT... feels like any other car...
The electric generator is connected to the sun gear. In electric mode, it can work as a motor above 70mph to assist the standard electric motor. Basically the sun gear unlocks and by sending electricity into the generator it becomes a motor. It is also connected directly to the ICE (well via a clutch)... so in range extending mode below 70mph it is simply driven by the ICE and generating power because the sun gear is locked, and above 70mph with the sun gear unlocked the ICE/generator combo is assisting to power the wheels.
Last edited by HAZ-Matt; Nov 3, 2010 at 03:55 PM.
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Re: Drove the VOLT... feels like any other car...
http://gm-volt.com/2010/10/15/clarif...ing-at-30-mph/
The engine WILL NOT turn on while the car is in electric driving mode (which for your trip two days ago approached 50 miles) – simply put, it is a full-performance battery electric vehicle.
Once the battery is depleted, the Volt’s gas-powered engine engages to create the power needed to extend the range of the vehicle several hundred additional miles. In extended range mode the Volt is powered by either a 1-motor series or 2-motor combined mode. The vehicle will select the most efficient mode for the driving condition: 1-motor series – for operations almost exclusively below 30 mph; 2-motor combined almost exclusively above 70 mph. At speeds in between 30-70 mph, the Volt will select the most optimally efficient drive mode amongst the two.
So it turns out the engine can contribute motive force to the Volt even at speeds from 30 to 70 mph presumably when the power demand calls for it such as hills and strong acceleration. Perhaps even more than that, Peterson wouldn’t say.
Volt chief engineer Andrew Farah explained this a bit more in an interview.
“The 70 mile an hour thing, we’re really not sure where that came from,” he said. “Somebody didn’t get the story right.”
He said there were specific determinants when the engine would provide input to the driveshaft. “Its’ really more an issue of torque and power than it is of speed,” he said.
The Volt has internal programming to determine at what points the engine should be coupled in. “It has an efficiency map, and based on the efficiency map it will decide what to do,” said Farah.
Once the battery is depleted, the Volt’s gas-powered engine engages to create the power needed to extend the range of the vehicle several hundred additional miles. In extended range mode the Volt is powered by either a 1-motor series or 2-motor combined mode. The vehicle will select the most efficient mode for the driving condition: 1-motor series – for operations almost exclusively below 30 mph; 2-motor combined almost exclusively above 70 mph. At speeds in between 30-70 mph, the Volt will select the most optimally efficient drive mode amongst the two.
So it turns out the engine can contribute motive force to the Volt even at speeds from 30 to 70 mph presumably when the power demand calls for it such as hills and strong acceleration. Perhaps even more than that, Peterson wouldn’t say.
Volt chief engineer Andrew Farah explained this a bit more in an interview.
“The 70 mile an hour thing, we’re really not sure where that came from,” he said. “Somebody didn’t get the story right.”
He said there were specific determinants when the engine would provide input to the driveshaft. “Its’ really more an issue of torque and power than it is of speed,” he said.
The Volt has internal programming to determine at what points the engine should be coupled in. “It has an efficiency map, and based on the efficiency map it will decide what to do,” said Farah.
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