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Discussion Starter #1 (Edited)
It is clear that increased acceleration drains the battery faster than slow acceleration. However a driver could accelerate at the same rate in sport and drive mode and theoretically, they would use the same amount of energy (ignoring the increased regen, of course).

The fact that sport mode can accelerate faster does not mean that the driver will take advantage of this feature. However sport mode could also be the equivalent of using a lower gear for an ICE car where the car goes the same speed and accelerates at the same rate but uses MORE ENERGY/GAS because the lower gear spins the engine faster. Higher RPMs use more gas though the car's forward movement is the same.

Does anyone know whether sport mode is designed to use more energy for the same forward movement (speed/acceleration) as compared to drive mode?
 

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Everything I've read about sport mode - which is almost entirely from this forum, is that on the Volt the sole thing it does is remap accelerator position versus power output. So it feels peppier for a smaller foot movement, and us drivers don't notice there's not much left as we keep pressing the pedal lower.

I used to work in the auto electronics industry, and this sort of mapping of the volume knob to gain was done. Users really do perceive the loudness of an audio system differently by this sort of remapping. I guess it works with our accelerator pedals, too.

This being said, I've not seen anything from GM engineering that makes this same claim - maybe someone else can point us to one. There used to be several GM employees posting on this forum, they always reconciled hearsay definitively.

-Lumos

2014 Gen 1
 

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At the very top of the DIC you can see the power being used - Drive it 60 mph on a flat road in Normal mode and note the power being used. Do it again over the same stretch of road in Sport mode and note the power being used. This A to B comparison should give you a more precise answer than dozens of us speculating what should be the answer to your question

Don
 

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It doesn't make any sense that it would use more energy to maintain the same speed. If it takes 19kW to hold 65 MPH in normal mode, it'll take 19kW to maintain that same speed on the same road/conditions using Sport mode. Else, where would the "extra" energy be going? Would they run the heater to get rid of it? Run the two motors against each other? Make the electric motors turn over the ICE?
;)

Mike
 

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It doesn't make any sense that it would use more energy to maintain the same speed.
;)

Mike
I agree. Sport mode just changes throttle mapping. It's the driver's foot that influences energy consumption. I'd think that selecting sport mode is unlikely to be accompanied with a light foot on the accelerator. I'm pretty sure if you set the cruise control and switch back and forth from normal to sport the power draw won't change.
 

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so we agree that over footing will use more energy ?
 

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Discussion Starter #7
It doesn't make any sense that it would use more energy to maintain the same speed. If it takes 19kW to hold 65 MPH in normal mode, it'll take 19kW to maintain that same speed on the same road/conditions using Sport mode. Else, where would the "extra" energy be going? Would they run the heater to get rid of it? Run the two motors against each other? Make the electric motors turn over the ICE?
;)

Mike
The Volt's CVT could be recalibrated to spin the motor faster keeping the wheels moving the same speed (but with added torque) in Sport Mode.
Quote: A continuously variable transmission (CVT) is a type of transmission that can provide an unlimited range of gear ratios in automobiles.

If the "gear ratio" in the CVT changes. the energy usage could change and use more energy during fast acceleration in sport mode.
 

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"Sport" mode encourages drivers to be a bit "friskier" and this overall driving style will use more energy. (you won't get as many miles per kWh ) ! But you WILL have more fun.
 

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You can achieve the same efficiency in sport mode. It's just that the probability of achieving is not likely!


The first thing I do after I sit down in my Volt is toggle sport mode on


One time I tried to drive in normal and it was too boring
 

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The Volt's CVT could be recalibrated to spin the motor faster keeping the wheels moving the same speed (but with added torque) in Sport Mode.
Quote: A continuously variable transmission (CVT) is a type of transmission that can provide an unlimited range of gear ratios in automobiles.

If the "gear ratio" in the CVT changes. the energy usage could change and use more energy during fast acceleration in sport mode.
But the Volt doesn't have a CVT. The Volt has a 1-speed transmission that takes advantage of the instant high torque of the electric motors to give the acceleration and tractability necessary.
 

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Discussion Starter #11
Quote from: https://gm-volt.com/2015/02/20/gen-2-volt-transmission-operating-modes-explained/

Don’t get too engrossed in the details of RE mode. While some think it is fascinating. Most do not and most don’t understand how a eCVT works so you are not alone. The simplest way for me to explain the eCVT in RE mode is that it allows the ICE to run at its most efficient operating points.

This Electronic CVT may have little in common with a mechanical CVT but there appear to be two clutches in the Volt's transmission that can be engaged and disengaged. Given that, it may be overkill to say that the Volt is "direct drive" and that its wheels are "locked" to the the one or both of its electric engines at all times during acceleration and forward movement.
 

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Quote from: https://gm-volt.com/2015/02/20/gen-2-volt-transmission-operating-modes-explained/

Don’t get too engrossed in the details of RE mode. While some think it is fascinating. Most do not and most don’t understand how a eCVT works so you are not alone. The simplest way for me to explain the eCVT in RE mode is that it allows the ICE to run at its most efficient operating points.

This Electronic CVT may have little in common with a mechanical CVT but there appear to be two clutches in the Volt's transmission that can be engaged and disengaged. Given that, it may be overkill to say that the Volt is "direct drive" and that its wheels are "locked" to the the one or both of its electric engines at all times during acceleration and forward movement.
Gen 1 the big Motor B is ALWAYS connected through the planetary gears to the wheels. There's no clutch in between B and the gearset, but there is between A and the gear.

Gen 2 eliminated that clutch between A and the gearset so BOTH motors are always connected to the wheels. SOMETIMES they're also clutched to something that doesn't move, so are essentially braked to not move at all. That doesn't mean they're not still connected though. There's not even really a clutch between the ENGINE and A, just a one-directional freewheel mechanism that means A will never spin SLOWER than the engine, but may spin faster.
 

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The Volt's CVT could be recalibrated to spin the motor faster keeping the wheels moving the same speed (but with added torque) in Sport Mode.
Quote: A continuously variable transmission (CVT) is a type of transmission that can provide an unlimited range of gear ratios in automobiles.

If the "gear ratio" in the CVT changes. the energy usage could change and use more energy during fast acceleration in sport mode.
The torque characteristic of electric motors suggest this wouldn't be necessary. At constant speed the energy required doesn't change regardless of gear ratio. If the driver is easy on the accelerator and keeps the same acceleration rate, think the energy use in sport mode would be the same.
 

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The Volt's CVT could be recalibrated to spin the motor faster keeping the wheels moving the same speed (but with added torque) in Sport Mode.
Quote: A continuously variable transmission (CVT) is a type of transmission that can provide an unlimited range of gear ratios in automobiles.

If the "gear ratio" in the CVT changes. the energy usage could change and use more energy during fast acceleration in sport mode.
All of that could theoretically be true, but it isn't (in the case of the Volt). Even if they did design it that way, they wouldn't leave the car in the less efficient mode at constant light throttle: it'd adjust to the most efficient setting when cruising so as not to waste energy. But the proof is in the pudding as they say: it takes 19kW of energy to keep my gen2 at 65 MPH on flat ground regardless of what drive mode is selected.

Mike
 
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