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Discussion Starter #1
I have a 158 mile commute each day, and I've been driving my Volt now for the last 3 days of my commute.
My daily routine is to drive on battery until I have roughly 5 miles left, and switch over to MM which gets the battery back up to a 20 mile range, enabling me to go back on the battery again. I do this twice on my commute to work and I make the first half of the commute using about 50 miles of battery and the other 28 miles on gas, thus keeping my fuel consumption to just under 1 gallon. On the way home, it's the same routine, but obviously more gas miles than battery miles.

I've noticed that the Energy Usage screen shows battery and fuel consumption for that charge, and I'm assuming it should total the battery miles each time I switch back to the propulsion battery, correct?

What I'm seeing is when I switch over to MM, the battery miles will stop accumulating, and the Gas miles will start accumulating. When I switch back to battery, the gas miles still accumulate, and the battery miles don't change, until I shut the car off and restart it for my commute back home, but it doesn't match what I'm actually getting just on the battery (yesterday was about 48 miles of battery, but the usage page showed 39 miles of battery).

I guess that's why I've seen it called the Guess-o-meter....

I assume this is a normal condition?

So far loving the Volt and really feel good about it as a long distance commuter car.
 

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I have a 158 mile commute each day, and I've been driving my Volt now for the last 3 days of my commute.
My daily routine is to drive on battery until I have roughly 5 miles left, and switch over to MM which gets the battery back up to a 20 mile range, enabling me to go back on the battery again. I do this twice on my commute to work and I make the first half of the commute using about 50 miles of battery and the other 28 miles on gas, thus keeping my fuel consumption to just under 1 gallon. On the way home, it's the same routine, but obviously more gas miles than battery miles.

I've noticed that the Energy Usage screen shows battery and fuel consumption for that charge, and I'm assuming it should total the battery miles each time I switch back to the propulsion battery, correct?

What I'm seeing is when I switch over to MM, the battery miles will stop accumulating, and the Gas miles will start accumulating. When I switch back to battery, the gas miles still accumulate, and the battery miles don't change, until I shut the car off and restart it for my commute back home, but it doesn't match what I'm actually getting just on the battery (yesterday was about 48 miles of battery, but the usage page showed 39 miles of battery).

I guess that's why I've seen it called the Guess-o-meter....

I assume this is a normal condition?

So far loving the Volt and really feel good about it as a long distance commuter car.
That sounds normal for a 2015 Volt. The part where you're running the battery down well past the MM set point and then using the engine to charge it back up is responsible for this behavior.

You see, 2013+ Volts keep track of where the energy came from, and so it accounts those miles being driven on the battery from energy that came from running the engine as gas miles since it burned gas to create them. If you ran it all the way down, you'd see that those last five miles that were left when you switched to MM would be accounted as EV miles again.

I think they did this to give a fairer "gas mileage" number - without it, it'd look like you were getting horrible gas mileage during that mountain mode section because of all the energy dumped into the pack and not used yet.

I believe it loses track when you power off, though, so anything in the battery when you come back gets counted as EV miles.
 

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Your 2015 Volt is operating as expected, and it could be that you would use about the same amount of gas for your round trip commute by not using Mountain Mode at all (i.e., the extra gas burned to recharge the battery for those battery powered "Gas" miles would give you about the same number of gas miles if you used it as Extended Range driving fuel).

For a Volt, "battery" miles can be recorded as Electric or as Gas Miles. The difference depends on the source of the electricity.

When you charge the battery from the wall socket, that’s "grid" electricity. Driving on grid battery power = Electric Miles.

When you use Mountain Mode to recharge the battery, that’s electricity you put into the battery by using gas, so when you switch back to Normal, you drive on gas-generated battery power = Gas Miles (note: 2011/2012 Volts count this as Electric Miles).

When you drive down a long hill you put regen into the battery, and when you reach the bottom of the hill and start driving on level terrain, you drive on regen battery power.

If you drove down that hill in Electric Mode, driving on that regen battery power = Electric Miles.

If you drove down that hill with a fully depleted battery, or in Hold Mode, the regen was created while driving in Extended Range Mode, and driving on that regen battery power = Gas Miles.

Just to be clear, the Volt’s "kWh Used" display = how much net grid power has been used, not how much total power from the battery has been used. Sometimes while driving down a long hill in Electric Mode you can see this number going down instead of up as regen is created.

Before you switched from Normal to Mountain Mode to recharge the battery, or before you started driving down a long hill in Hold Mode, your Volt’s computer had "flagged" the amount of usable grid battery power remaining in the battery (the "state of charge" level of the usable grid power).

If you turn your Volt off and back on again after Mountain Mode has recharged the battery but before you’re used this MM-recharged battery power, or after you’ve driven downhill in Hold Mode but before you’ve used this regen battery power, the computer will recognize the battery SOC is now above the minimum "switch to gas" SOC, and it is also above the flagged "grid power" SOC.

Because the battery is now above the "switch to gas" SOC, driving on the MM-generated battery power or the Hold Mode regen battery power after turning the Volt off and back on again will be recorded as Electric Miles.

While driving on the MM-generated battery power or Hold Mode regen battery power after turning the Volt off and back on again, the "kWh Used" number will not change until this power is used up and the battery SOC has dropped to the "grid power" SOC level. At that point, the distance driven will continue to be recorded as Electric Miles, and the kWh Used number will again increase as the grid power is used.

This "glitch" from turning the car off and on again enables a driver to inflate the ev mileage (increases the total Electric Miles without increasing the grid power kWh Used number). It also deflates the gas mileage by shifting Gas Miles to the Electric Miles totals (fewer Gas Miles driven without reducing the Gas Used number).
 

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By using MM to charge up the battery several times each day you are using more gas than if you just used Hold Mode because the ICE has to work harder. If you can't charge at work then just use gas for most of the outbound trip, save majority of the battery for the start of the return trip back home. The last ~28 miles of the return trip would be on gas, then you can recharge when you reach home.
 

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In my old ‘13 I tried MM vs. no MM on my commute numerous times under similar conditions and found using MM burned more gas per trip. It’s always a challenge in a volt when your regular commute is outside EV range to get the best results.

Generally, using MM can only possibly be beneficial if you use gas-generated EV miles under ideal conditions for EV range—this is very hard to do and my results found the challenge not worth it. Now, if you just like EV and want more quiet time, fine. Otherwise just using hold will always use less gas per trip.
 

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Discussion Starter #6
Guys;
Thanks for the responses. Man I'm learning more about this car each day... I see where you're coming from with the MM using more gas. During my commute this morning, I depleted the battery and allowed the car to switch on it's own. The battery stayed at 0 miles even after switching to MM and recharging. I switched back to Normal and was able to finish the last 15 miles or so on battery, even when it showed 0 miles available. (slightly confused about that one...)

Each of the last 3 days I used 2.8 - 2.9 gallons of gas over the 158 mile commute. We'll see how HM does tomorrow...

I filled the tank yesterday (I use Fuelly.com to track my fuel usage) and I recorded an average of 64.5 mpg for 508 miles over 3 days. Granted that includes the Grid power, but never the less, I'm way ahead of where I was with my LS430, where I averaged 25 MPG.
 

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By using MM to charge up the battery several times each day you are using more gas than if you just used Hold Mode because the ICE has to work harder. ...
Because charging and discharging any battery is never 100% efficient at what goes in/what comes out.

In summary: You're doing it wrong. :p:)

I like the idea of saving ~5 miles of EV range for the end of your commute so you can arrive in silent style !,,
and have a somewhat cooled down engine compartment from that last bit of moving through the air not making/wasting heat!
 

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Words you never seem to hear on a car trip

"How many pounds of fule do we have left ? "
 

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Discussion Starter #9
Well, the last few days of commuting, I've used the Hold mode first, and then switched over to battery at 40 miles from home. My fuel consumption improved .2 (2.9 down to 2.7 gals. of fuel) on the 158 mile trip.

It is an improvement, but not a drastic improvement. I suppose I could see more improvement on days where I'm not using AC or heat.
 

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Well, the last few days of commuting, I've used the Hold mode first, and then switched over to battery at 40 miles from home. My fuel consumption improved .2 (2.9 down to 2.7 gals. of fuel) on the 158 mile trip.

It is an improvement, but not a drastic improvement. I suppose I could see more improvement on days where I'm not using AC or heat.
Not using MM increased your efficiency when using gas by 7%. Auto engineers would kill for 7% improved fuel economy. For the entire trip your Volt returned 58.5 MPG combined. Try and find another hybrid vehicle or plug-in hybrid that does better.

The AC does not use nearly as much of the battery as the electric heat so enjoy being cool in your Volt. Since you save the battery for the last 40 miles of your return trip home the heat from the Volt's engine will keep you warm for all but the last part of the return trip, the warm coolant will continue to circulate in the cabin heat exchanger after you switch to running on the battery. This should keep you comfortably warm for at least half of the last 40 miles to home. You can pulse the electric cabin heat on and off briefly if it gets too cold or if the windows start to fog up before your reach your final destination.

If this same 158 mile round trip was driven in a Gen 2 Volt, assuming 53 miles range using the Gen 2 Volt's battery, the Gen 2 Volt would achieve 63.2 MPG (while using regular gas.) This would be approximately 7.5% better fuel economy than the Gen 1.

Other tips for improving your overall economy: inflate your tires up to the maximum rated cold pressure, limit your highway speed to under 65 MPH (when possible, given traffic conditions), keep the Volt's exterior clean (this can really make a difference.)
 

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You should establish a "control" baseline set of numbers for your commute by driving it a couple of times or so without using Hold at all, i.e., drive to work on battery until it’s depleted, then continue on there, and come home at the end of the day with the engine running. By not "saving your battery for later use," your 158 mile round trip numbers will be, per trip, perhaps, around 40 Electric Miles, 118 Gas Miles, and maybe around 2.8 gallons used. You could also experiment with the use of heat or a/c during such a commute to evaluate their influence on the ev mileage and gas consumption.

Then if you must experiment with Hold Mode, see if you can reduce gas consumption numbers by switching to Hold Mode during the portion of the commute that is favorable to efficient gas driving (e.g., when cruising at steady speeds)... don’t be afraid of exchanging a couple of electric miles for gas miles if by doing that, you increase the portion of the commute spent driving in "good gas mileage" driving conditions...
 

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Discussion Starter #12
You should establish a "control" baseline set of numbers for your commute by driving it a couple of times or so without using Hold at all, i.e., drive to work on battery until it’s depleted, then continue on there, and come home at the end of the day with the engine running. By not "saving your battery for later use," your 158 mile round trip numbers will be, per trip, perhaps, around 40 Electric Miles, 118 Gas Miles, and maybe around 2.8 gallons used. You could also experiment with the use of heat or a/c during such a commute to evaluate their influence on the ev mileage and gas consumption.

Then if you must experiment with Hold Mode, see if you can reduce gas consumption numbers by switching to Hold Mode during the portion of the commute that is favorable to efficient gas driving (e.g., when cruising at steady speeds)... don’t be afraid of exchanging a couple of electric miles for gas miles if by doing that, you increase the portion of the commute spent driving in "good gas mileage" driving conditions...
Good thoughts... I will continue to experiment. In any case, I'm pleased as punch with the car, and it gives me something to do during the commute!
 

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I've come to understand my guess o meter's workings.

I live in the hills so anywhere I go it's downhill to start with.

So after starting with 38 miles on the battery after about 4 miles or so it might be up to 44 miles on the battery.

The meter is saying, "If the rest of the trip is like this we can go 44 miles!"


If I'm going on a longer journey I burn my gas early and come home on battery, spent a lot of time calculating how to get home with battery almost empty. I try and use the ICE when I'm cruising on the freeway, not climbing hills. I'm always going in the morning so I use the ICE when it's cooler so should be easier on the engine.
 

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".... keep the Volt's exterior clean (this can really make a difference.)" Can you please elaborate? We love our 2016. It is our only car and we are able use it primarily as an EV, resorting to petroleum only for occasional long-distance trips. Except for removing winter road salt, I'm negligent about washing the exterior (or the interior, for that matter). Does grime on the exterior really contribute measurable drag (or weight)?
 

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".... keep the Volt's exterior clean (this can really make a difference.)" Can you please elaborate? We love our 2016. It is our only car and we are able use it primarily as an EV, resorting to petroleum only for occasional long-distance trips. Except for removing winter road salt, I'm negligent about washing the exterior (or the interior, for that matter). Does grime on the exterior really contribute measurable drag (or weight)?
Yes, Mythbusters even did a feature where they disproved the myth that there was a significant improvement in fuel economy when driving a very dirty car versus a clean car.

"They did 10 runs down a 1 mile track, 5 dirty 5 clean. The dirty car did worse than the clean car,getting 24mpg. The clean got 26. BUSTED!" 8.3% better fuel economy for the clean car.

Next the Mythbusters tested if the golf ball effect that the dirt was suppose to have works on a car. they covered a car in clay and smoothed it down so that it was the same shape as the car body. They did the same test as before, 5 runs smooth, and 5 with golfball dimples. Smooth-26mpg, Dimpled-29mpg.
 

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Yes, Mythbusters even did a feature where they ...."They did 10 runs down a 1 mile track, 5 dirty 5 clean. ....
Love those guys!
But seriously, this testing sounds BOGUS.
How can you possibly test fuel economy during a "1 mile" drive?
 

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Love those guys!
But seriously, this testing sounds BOGUS.
How can you possibly test fuel economy during a "1 mile" drive?
With a precisely measured amount of fuel, results averaged for 5 separate runs.
 

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With a precisely measured amount of fuel, results averaged for 5 separate runs.
Still, the % of error for a 1 mile measurement???

And wind and temps need to be identical or both directions in quick order...

Why make it more difficult than it needs to be.

Hell, they probably had the money for a few hours in a wind tunnel and really get all SCIENTIFIC !!

Love those guys, though!!!
Penn & Teller's Bxxx Sxxx too!!
 

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Still, the % of error for a 1 mile measurement???

And wind and temps need to be identical or both directions in quick order...

Why make it more difficult than it needs to be.

Hell, they probably had the money for a few hours in a wind tunnel and really get all SCIENTIFIC !!

Love those guys, though!!!
Penn & Teller's Bxxx Sxxx too!!
Assuming an average of 25 MPG, that would be 151.4ml of fuel per run. It would be easy to observe a 12.6ml (8.3%) difference in fuel consumption on a graduated cylinder feeding the fuel intake. Over the 5 runs that would be a little more than 2 oz difference in fuel consumption, small but measurable. A longer distance test would have been preferable but would have involved more variables such as wind.
 

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...... Over the 5 runs that would be a little more than 2 oz difference in fuel consumption, small but measurable. A longer distance test would have been preferable but would have involved more variables such as wind.
OK, I'm convinced...:rolleyes: Totally scientific method of measuring MPG.
'graduated cylinder' feeding a Fuel Injection System?:confused: What about the return line?
And isn't wind always a factor?
Love the show, but I'm with P&T and sometimes you gotta call BS.
 
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