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Wait a minute! You are demonstrating something many of us already know. Using Mountain Mode to recharge your battery has a moderate effect on MPG but will lower your MPGcs.

Your example: Round trip of 229 miles, 120 of which is driven on electric power, leaving 109 gas powered driving miles. 109 gas miles/4.8 gallons = 22.7 MPGcs. Would be informative to see how your center stack usage screen broke down the 229 miles. The kWh Used number tracks grid power use. In my 2012 Volt it won’t increase when I drive MM-recharged power electric miles (once did 86.9 electric miles on 9.8 kWh Used!). What was your 229-mile drive AER and kWh Used?

There is a driving speed at which, when matched with appropriate and terrain and environment variables, a Gen 1 Volt could switch between Normal and Mountain Mode every 15 minutes and accomplish half of the post-full-battery portion of the trip using battery power and half using the ICE, if the goal is to reduce the running of the ICE. "Volting" under other conditions would also reduce the running time of the ICE by substituting periods of recharged battery use.

Driving downhill also cuts the time the ICE is running, and some Volt drivers switch from Hold to Normal just before cresting the hill to put that downhill distance plus regeneration into the electric mile column to increase the AER. Perhaps they don’t realize that remaining in Hold includes that downhill plus regenerative power driving in the gas miles column and increases the MPGcs!

It’s debatable if "Volting" uses less gas than simply remaining in Normal. Generally speaking, the average Gen 1 Volt consumes 1 gallon of gas to drive 40 miles in ICE mode and (if it were possible) 1 gallon of gas to fully recharge a depleted battery (40 miles of battery power) using MM. If so, then gas consumption is a wash.

The Self-Charging Volt video shows a 2012 Volt using MM to recharge a fully depleted battery to the MM-maintained level while parked, using ~15 minutes and 0.36 gallons of gas to do it. You write that when the engine is powering the Volt in Mountain Mode at 60-65 mph, the primary work load is to move the vehicle. I suggest the primary work load of the engine is to generate electricity, which enables the traction motor to move the vehicle down the road. Fuel consumption rates of a gas generator under varying power loads could use a little clarification when applied to the Volt’s gas engine operation. I don’t know if anyone has demonstrated that using MM to recharge while driving down the road changes the amount of time and volume of gas from that needed to recharge while parked. The cost of 1 gallon of gas is much greater than the cost most of us pay at home for recharging the battery via the grid, i.e., driving 40 miles on a full charge is cheaper than driving 40 miles using 1 gallon of gas.
 

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Discussion Starter · #22 ·
While I applaud your achievement, it might be a good idea to point out (especially to new Volt owners) that you have not gained any additional electric miles, in the conventional sense of the term (miles traveled without burning gasoline). What you have done is judiciously used Mountain Mode and rest stops, where you power off and power back on in Normal mode, to burn as little gas as possible. Any "extra" EV miles that the car records is the result of a glitch in the Volt's mileage counting process, in which, after you turn off the car and turn it back on, it "forgets" that the available electric charge was gas-generated. Feel free to correct me if I'm wrong, but there have been lots of threads that document this process, with people thinking that they're getting "free" electric miles when, in fact, they are just gaming the system.
Thanks for your reply - You really have no concerns on hurting the battery. Keep in mind that GM already short cycles their batteries to begin with and we're only charging to 45%, so generally speaking, the battery is totally unaffected by this Volting charge.

While all batteries a have a life cycle, you'll never wear the Volt or ELR battery down in the lifetime of the car. Remember electrics like the Prius charge and discharge their batteries almost hourly and last the lifetime of the car.

Regards!
 

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Discussion Starter · #23 ·
Wait a minute! You are demonstrating something many of us already know. Using Mountain Mode to recharge your battery has a moderate effect on MPG but will lower your MPGcs.

Your example: Round trip of 229 miles, 120 of which is driven on electric power, leaving 109 gas powered driving miles. 109 gas miles/4.8 gallons = 22.7 MPGcs. Would be informative to see how your center stack usage screen broke down the 229 miles. The kWh Used number tracks grid power use. In my 2012 Volt it won’t increase when I drive MM-recharged power electric miles (once did 86.9 electric miles on 9.8 kWh Used!). What was your 229-mile drive AER and kWh Used?

There is a driving speed at which, when matched with appropriate and terrain and environment variables, a Gen 1 Volt could switch between Normal and Mountain Mode every 15 minutes and accomplish half of the post-full-battery portion of the trip using battery power and half using the ICE, if the goal is to reduce the running of the ICE. "Volting" under other conditions would also reduce the running time of the ICE by substituting periods of recharged battery use.

Driving downhill also cuts the time the ICE is running, and some Volt drivers switch from Hold to Normal just before cresting the hill to put that downhill distance plus regeneration into the electric mile column to increase the AER. Perhaps they don’t realize that remaining in Hold includes that downhill plus regenerative power driving in the gas miles column and increases the MPGcs!

It’s debatable if "Volting" uses less gas than simply remaining in Normal. Generally speaking, the average Gen 1 Volt consumes 1 gallon of gas to drive 40 miles in ICE mode and (if it were possible) 1 gallon of gas to fully recharge a depleted battery (40 miles of battery power) using MM. If so, then gas consumption is a wash.

The Self-Charging Volt video shows a 2012 Volt using MM to recharge a fully depleted battery to the MM-maintained level while parked, using ~15 minutes and 0.36 gallons of gas to do it. You write that when the engine is powering the Volt in Mountain Mode at 60-65 mph, the primary work load is to move the vehicle. I suggest the primary work load of the engine is to generate electricity, which enables the traction motor to move the vehicle down the road. Fuel consumption rates of a gas generator under varying power loads could use a little clarification when applied to the Volt’s gas engine operation. I don’t know if anyone has demonstrated that using MM to recharge while driving down the road changes the amount of time and volume of gas from that needed to recharge while parked. The cost of 1 gallon of gas is much greater than the cost most of us pay at home for recharging the battery via the grid, i.e., driving 40 miles on a full charge is cheaper than driving 40 miles using 1 gallon of gas.
Thanks for the reply but facts are facts - why would anyone buy an electric car and deliberately run their engine when they have the option to travel in electric mode and avoid hours of use on their engine at a greater expense for fuel? My mpg readings are gospel and don't lie. I included my addendum below to help understand it.

Thanks!

Addendum: While I didn’t want to get over-technical with this article, there is reader concerns how Volting can occur using less fuel so I’m going to offer a scenario which will help clear up the matter.

Lets take a situation where we’re driving down the road at 60 mph in mountain mode. We’ll say the battery is below 45%, so our little I4 engine is both charging the battery and pushing the car at 60 mph. While this does not sound so amazing, lets look at it a bit closer; the engine is generating (charging) at a rate of “one mile of charge per minute” therefore this is enough energy to propel another car (or ours) at 60 mph going in the battery each minute.

Therefore, at any given moment our little engine in Mountain mode is producing enough power to propel two (2) cars at 60 mph or 120 mph of energy, since its moving the car at 60 mph and storing energy to propel the car at some time in the future at 60 mph. The real important fact here is its doing so using about the same amount of fuel it takes to move one car.
 

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Nice writeup Mike!!
I gave always traveled this way as you can't always plugin while on the road and I gain similar results as you
As soon as I get the maximum ev recharge, which is 27 miles for my 2015 volt I go back into ev mode until I have around 5 miles ev left, then back into mountain mode for about 20 minutes and I am back in ev mode again.
 

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Thanks for the reply but facts are facts - why would anyone buy an electric car and deliberately run their engine when they have the option to travel in electric mode and avoid hours of use on their engine at a greater expense for fuel? My mpg readings are gospel and don't lie. I included my addendum below to help understand it.

Thanks!

Addendum: While I didn’t want to get over-technical with this article, there is reader concerns how Volting can occur using less fuel so I’m going to offer a scenario which will help clear up the matter.

Lets take a situation where we’re driving down the road at 60 mph in mountain mode. We’ll say the battery is below 45%, so our little I4 engine is both charging the battery and pushing the car at 60 mph. While this does not sound so amazing, lets look at it a bit closer; the engine is generating (charging) at a rate of “one mile of charge per minute” therefore this is enough energy to propel another car (or ours) at 60 mph going in the battery each minute.

Therefore, at any given moment our little engine in Mountain mode is producing enough power to propel two (2) cars at 60 mph or 120 mph of energy, since its moving the car at 60 mph and storing energy to propel the car at some time in the future at 60 mph. The real important fact here is its doing so using about the same amount of fuel it takes to move one car.
I don't think you are considering the losses in recharging the battery. I may be wrong but I do think that it is more efficient to save a battery charge if possible and only produce the electricity needed to propel the car down the road having the ICE cycle on and off as necessary, than fully depleting a battery and charging it back up.
 

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Nice writeup Mike!!
I gave always traveled this way as you can't always plugin while on the road and I gain similar results as you
As soon as I get the maximum ev recharge, which is 27 miles for my 2015 volt I go back into ev mode until I have around 5 miles ev left, then back into mountain mode for about 20 minutes and I am back in ev mode again.
But that 27 miles is really still done by burning gas. Doesn't matter how the car tallies it.
 

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With all the comments about gaming the numbers, I'm not convinced that defying the laws of physics is possible. Though I would love to see GM add a full charge mode to just drive with the ice and opportunitically charge the battery all the way up, especially when regen-ing or just idling a bit higher than needed when cruising to turn the genset. I'd want this to take a trip to Chicago, using up the battery for the first 40 some odd miles, then slowly charge so when I arrive at Chicago 120 miles later the battery is charged for another 40 miles of silent battery use.
 

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Thanks for the reply but facts are facts - why would anyone buy an electric car and deliberately run their engine when they have the option to travel in electric mode and avoid hours of use on their engine at a greater expense for fuel? My mpg readings are gospel and don't lie. I included my addendum below to help understand it.

Thanks!

Addendum: While I didn’t want to get over-technical with this article, there is reader concerns how Volting can occur using less fuel so I’m going to offer a scenario which will help clear up the matter.

Lets take a situation where we’re driving down the road at 60 mph in mountain mode. We’ll say the battery is below 45%, so our little I4 engine is both charging the battery and pushing the car at 60 mph. While this does not sound so amazing, lets look at it a bit closer; the engine is generating (charging) at a rate of “one mile of charge per minute” therefore this is enough energy to propel another car (or ours) at 60 mph going in the battery each minute.
Why would anyone buy an electric car and deliberately recharge it via gas generator at about twice or three times the price of recharging it at home? Yes, your mpg readings don’t lie - your gas mileage when on that 229 mile trip was less than 23 mpg.

If the engine is generating at a rate of "one mile of charge per minute," and the traction motor is consuming it all (uses one mile of charge per minute as it moves 60 miles down the road in 60 minutes @ 60 mph), how can MM recharge the battery at all without somehow generating power even faster? Wouldn’t you need to generate TWO miles of charge per minute during the ~15 minutes needed to move the car AND recharge ~15 miles into the battery?
 

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Great you discovered "gaming" mountain mode, (which many on here have been tinkering with and mastering since 2010) and a great many others have found it simply too fuel inefficient as mountain mode runs the ICE at a higher RPM and generator output load compared to CS. (so cut this "volting" business- It isn't going to fly.)
Additionally I deleted the link in your signature. We do not permit off-site links to personal or business websites
AND PLEASE refrain from creating duplicate posts on this forum! (final warning)
Thank You
WopOnTour
 

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Therefore, at any given moment our little engine in Mountain mode is producing enough power to propel two (2) cars at 60 mph or 120 mph of energy, since its moving the car at 60 mph and storing energy to propel the car at some time in the future at 60 mph. The real important fact here is its doing so using about the same amount of fuel it takes to move one car.
I am afraid you are mistaken here. There is no such thing as free generation of energy, the laws of physics are pretty clear :)

If you are running on ICE at 60 mph, the ICE generator will be running at speed X, using Y amount of gas
If you would be running on ICE at 60 mph AND charging the battery with enough energy to propel another car at 60mph, the ICE generator would have to be running at twice the speed, using twice as much gaz as in the first scenario.

There is no way around that :)
 

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I don't want to rain on your parade but I see nothing particularly special about this, and you are simply making the fuel consumption more sensitive to the particular trip you are making.

For the particular profile of route that you are taking, perhaps you are, indeed, beating the Voltec programming. But it's really not very good programming so it's not that difficult to beat it!

The way to get optimum *specific fuel economy* from the ICE (I'll explain that in a minute) is to ensure that whenever the engine is operating the power meter is showing neither green nor yellow on the battery side whilst also being in power split mode (which typically occurs over 35mph at steady, low power demand situations - you don't have any control over that). Let's call this 'Efficiency mode (1)'.

(2) The next best way is to ensure there is a little yellow showing, but it's not possible to 'make' the car do that (unfortunately) it just happens during routine driving.

(3) The worse way to do this is to allow green to show on the battery side while in power split mode. The 'bigger' the green the worse it is. If too much green, it will overlap with (4).

(4) The even worse way is to allow green or yellow to alternate whilst shutting the engine on and off, as it keeps dropping out of power-split mode when it does this.

Guess which way GM have done this ...... yup, it's picked (4)! I think they have done this primarily for consistency of outcome. You can drive it badly, or drive it well in this mode and it gives pretty consistent energy efficiency. Not much you can do to make the fuel economy much better, even driving slower doesn't really help that much!!

What you're doing in your 'Volting' process is getting the car to mostly do (3). So, yes, you should end up a little better so long as you don't push the engine into delivering 'lots of green' (i.e. wasting too much energy via charge/discharge).

The problem with this is a double-edged thing. You want the engine to run as steady and as constant as you can, for as long as you can. MM helps here, but if you let the charge level drop too low the car is programmed to run the engine harder and deliver more charging power. More charging power (more green) = less efficient.

So you can use MM to either run more efficiently than the Voltec hold mode if you are a little below the MM threshold but it won't run like that for too long until it catches up, but let the charge level drop lower still so the engine runs for longer and it will run less efficiently.

There's a sweet spot for the process you are describing, and it is starting MM at around, I'd guess, 75% discharged.

It is very frustrating that GM did not program in some additional modes allowing a slow discharge. If there was some setting to prevent 'hold' from going over 12kW and instead allowing the battery to gradually decline, this would be the most efficient.

The engine is also almost totally silent at that engine power too, so it could be set to spin over at that power setting all day, extending the effective one-charge range by 3 before the battery power is depleted. I recognise what you are saying about the benefit of not having to hear that engine running, but if you run it at lower power loads you don't really hear it anyway.

So, yes, I agree you can outwit the rather dumb programming of the Voltec, but, no, there is NO WAY that you are powering two cars-worth of power for the fuel consumption of one.

(Oh, I did mention I'd explain *specific fuel economy*. Here's the rub - if you are driving along the highway and the engine comes on, the ideal is that you try to match the power needed with the pedal position, i.e. keep the engine perfectly balanced with the power demand. In this way, nothing goes via the battery and you get no charge/discharge losses. But if you do this, sometimes you will find yourself building up speed because the car is attempting to charge itself and as you press harder to send more power to the wheels, instead the car ramps up the engine more to charge the battery up!! On a pure flat, you will probably end up in a scenario where you are doing around 70~75mph and drawing 16kW. Now, driving at 70mph isn't the most efficient speed so it will not result in the best 'fuel economy', but at this point you are actually converting the energy content of the fuel to traction power as efficiently as possible, you simply need more of it. This is the maximum *specific fuel economy*, i.e. if you wanted to do 70mph then that's great! But it is not necessarily the most economic especially if you didn't want to drive that fast!)
 

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Hello guys - I added this addendum to help explain the fuel savings;


The real important fact here is its doing so using about the same amount of fuel it takes to move one car.
This does not pass the basic engineering smell test. This is not the way things work. If you are running the generator, there is more load on the engine (on average) and it will use more fuel.
 

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Discussion Starter · #33 ·
Great you discovered "gaming" mountain mode, (which many on here have been tinkering with and mastering since 2011) and a great many others have found it simply too fuel inefficient as mountain mode runs the ICE at a higher RPM and generator output load compared to CS. (so cut this "volting" business- It isn't going to fly.)
Additionally I deleted the link in your signature. We do not permit off-site links to personal or business websites
AND PLEASE refrain from creating duplicate posts on this forum! (final warning)
WopOnTour
***

Thanks for the reply - I'm not saying I discovered MM - I opened this article with the statement that guys have been using MM for the same purpose - the Volting technique just shows it put to a more piratical use and to show its more cost effective and a more enjoyable way to travel.

My personal link was just for interest purposes to share information on electric Drones - I'm not in any business or selling anything or in any way attempting to draw users from the forum.

I would never double post anything on this forum - since the article was for Volts and ELR's, I posted in both discussion forums, since its very unlikely that an ELR owner would visit this forum and vice versa.

My gosh I'm taken back and very hurt that you would issue a warning to remove me from the forum for only sharing information about the very same cars we discuss every day - It takes months to do these articles!

Regard Mike
 

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***

Thanks for the reply - I'm not saying I discovered MM - I opened this article with the statement that guys have been using MM for the same purpose - the Volting technique just shows it put to a more piratical use and to show its more cost effective and a more enjoyable way to travel.

My personal link was just for interest purposes to share information on electric Drones - I'm not in any business or selling anything or in any way attempting to draw users from the forum.

I would never double post anything on this forum - since the article was for Volts and ELR's, I posted in both discussion forums, since its very unlikely that an ELR owner would visit this forum and vice versa.

My gosh I'm taken back and very hurt that you would issue a warning to remove me from the forum for only sharing information about the very same cars we discuss every day - It takes months to do these articles!

Regard Mike
Idleup

It is a good article and definitely got some good discussion going. If you had not put this together we might have missed out on many good points from you and others on the discussion. Thanks for putting it together.
 

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Most of the comments here have hit the nail on the head. You can't beat physics. The 41 to 42 mpg you report is about what I get on long trips in hold mode at 70 mph or so, the speed limit in Ohio. The GM engineers designed power split mode, where the engine drives the planetary gears that drive the wheels through the generator, using kinetic energy from the engine both to drive the wheels, the most efficient use of gas, and to generate electricity to drive the electric motor and charge the battery. This mode is about 15% more efficient than running as a series hybrid, generating electricity to drive the electric motor alone, according to GM's calculations. The car can't run in power split mode in mountain mode, because the goal there is to run the engine fast to charge the battery in preparation to go up a mountain, not to be efficient.

Have fun playing with your car. Just realize that mountain mode in most scenarios is less efficient than hold mode.
 

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You might be consuming 2x the fuel to charge and cruise at 60mph but going 120mph would require 4x the power and about that much more fuel.
Actually, while the drag increases as the velocity squared, the power required to overcome it increases as the velocity cubed.

A 125 hp car can hit 120 mph, but it takes 1000 hp to hit 240 mph (Bugatti).

Consider,

Power = force * velocity

If the force is that of drag (Fd), to keep a constant velocity, then

P = Fd * v

Fd = K * v * v, where K = 1/2 * coefficient of drag * frontal area of the car * air density

So,

P = K * v*v*v
 

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The car can't run in power split mode in mountain mode, because the goal there is to run the engine fast to charge the battery in preparation to go up a mountain, not to be efficient.
Yes it can. It is less likely to do it at high power demands than simple 'HOLD', but if the SOC is not too low the engine runs at a modest power setting and will run just like hold, albeit at the next power set point up to assist in battery charging.

It is not so dumb that it simply runs flat out as fast as it can, it eases off as it increases the SOC.
 

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I guess my takeaway is that without mountain mode I have gotten up to 64 miles EV range and 51mpg (just gas) for a combined total of 150mpg.

I did that without the use of mountain mode, just carefull driving in EV, Hold then EV again.
 

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Three comments:

To Ampera Jed: Regarding your earlier comment, others and I have discussed the mode you (and we) are wishing for. A few of us called it “hold lite” (search the forum). It would basically allow an on-demand ERDDT level of engine running to slow the discharge rate while the engine runs at a relatively low, steady, and quiet speed. I can’t believe it wouldn’t have as decent or better gas mileage than the Hold Mode's cold starting, stopping, and revving up and down.

I’m not sure about the lower engine wear the OP mentions with his method. MM runs the engine at a much higher RPM under a much heavier load than HM. Does an engine running twice as hard but for half as long have less wear?

As for comments about breaking the laws of physics … it’s not as simple as that. In the case of MM vs. HM, adding an additional charge load that, say, is twice the energy requirement, might not require twice the input. Some of the heat and friction losses of just running the engine don’t necessarily have to be paid for twice. You might be able to double the output at something less than 100% added input.
 

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A few of us called it “hold lite” (search the forum). It would basically allow an on-demand ERDDT level of engine running to slow the discharge rate while the engine runs at a relatively low, steady, and quiet speed. I can’t believe it wouldn’t have as decent or better gas mileage than the Hold Mode's cold starting, stopping, and revving up and down.
I like that idea. That way if you know you are going on a short trip just beyond the range of the charge range you could engage it for a portion of the trip.
 
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