GM Did It Again! Volt discussion thread

[LS2JSTS]

Originally Posted By: Bill in Utah
Originally Posted By: LS2JSTS
Originally Posted By: Bill in Utah
Originally Posted By: LS2JSTS

.... It can't maintain speeds above 70 mph without the IC engine.


Yes and no, when the battery is at full charge the car can run completey on battery power up to 100 mph iirc. Once the battery is below a certain charge level THEN the ice is required above 70 mph.



From the OP

Quote:
The 4ET50 is, however, in fact directly bolted to the 1.4-liter, four-cylinder Ecotec internal combustion engine. When the Volt's lithium-ion battery pack runs down, clutches in the 4ET50 engage and the Ecotec engine is lashed to the generator to produce the electric power necessary to drive the car. However under certain circumstances — speeds near or above 70 mph — in fact the engine will directly drive the front wheels in conjunction with the electric motors.


Yes Bill, I understand, notice it says "under certain circumstances"?

Those circumstances are when the battery is below a certain level. It is a fact that the Volt with a FULL charge will do 100 mph with the ICE completely off.


I'm getting that under certain circumstances LIKE being near or over 70 MPH the IC engine WILL directly drive the front wheels with the electric motors.

That would be one of the certain circumstances...

That may be the way that slanted original article wrote it up...but it isnt fact. From all I've read, when the battery is fully charged the car runs under battery power at any speed, it's only after the battery has lost a certain amount of charge that the ICE kicks on regardless of road speed. I'll dig into it some more...but frankly the original article has little credibility with me.

 

[Bill in Utah]

Originally Posted By: LS2JSTS
I'll dig into it some more...but frankly the original article has little credibility with me.


Sadly most media "articles" run into that problem with me also...

Too much agenda and not enough fact...

 

[LS2JSTS]

Originally Posted By: KrisZ
The reason the number is meaningless is because GM is trying to measure something that is not in use most of the times.

Is there anyone willing to take a 2,000 mile trip in 50 mile hops?




I get your point, but the only thing meaningless here is your effort to fit the Volt into a shoebox of potential uses. Ignoring the fact that many will use the Volt to NOT take 2,000 mile trips 90% of the time. The added ability to take that 2,000 mile trip in your electric car is a luxory above and beyond what other electric cars are currently capable of. It's an ADDED convenience, it is not intended to be the sole use or purpose of the Volt. And in real world use, by the average buyer, it will just be one small sliver of actual use but that doesnt make for a good thread does it?

Could you please provide data that proves your contention that the electric motor wont be in use most of the time for the average user? Of course if your only willing to look at 2,000 mile trips you are right. But what about the guy who is driving the Vlt back and forth to work everyday...maybe his profile would yield different numbers? But that would be meaningless?

 

[KrisZ]

Originally Posted By: LS2JSTS
Originally Posted By: KrisZ
The reason the number is meaningless is because GM is trying to measure something that is not in use most of the times.

Is there anyone willing to take a 2,000 mile trip in 50 mile hops?




I get your point, but the only thing meaningless here is your effort to fit the Volt into a shoebox of potential uses. Ignoring the fact that many will use the Volt to NOT take 2,000 mile trips 90% of the time. The added ability to take that 2,000 mile trip in your electric car is a luxory above and beyond what other electric cars are currently capable of. It's an ADDED convenience, it is not intended to be the sole use or purpose of the Volt. And in real world use, by the average buyer, it will just be one small sliver of actual use but that doesnt make for a good thread does it?

Could you please provide data that proves your contention that the electric motor wont be in use most of the time for the average user? Of course if your only willing to look at 2,000 mile trips you are right. But what about the guy who is driving the Vlt back and forth to work everyday...maybe his profile would yield different numbers? But that would be meaningless?


I agree with you as well for the usage pattern that Volt probably will be used for, but usage pattern is absolutely critical in that figure, something that GM is not exactly clear on.

In regular cars you get city mileage (worst case scenario) and highway mileage (best case scenario), most people can easily get something in between, no matter their usage pattern. With Volt it's a totally different story, usage pattern is critical, something that is unique to Volt and unconventional, yet GM insists on using a conventional method of calculating fuel mileage in Volt, they should do better, that's all I'm saying.

 

[Bill in Utah]

And I agree here. One thing about a Hybrid or Volt that a TRUE 100% electric vehicle can DO is go that 2000 miles. True it will get 38.x MPG (or whatever the vehicle gets) but at least it CAN do another mission UNLIKE 100% electric vehicles.

That would make it MUCH more valuable to me. Anything that had only a 50 mile one way range in PERFECT conditions would have me ending my commute way short.

Bill

 

[LS2JSTS]

Originally Posted By: KrisZ
Originally Posted By: LS2JSTS
Originally Posted By: KrisZ
The reason the number is meaningless is because GM is trying to measure something that is not in use most of the times.

Is there anyone willing to take a 2,000 mile trip in 50 mile hops?




I get your point, but the only thing meaningless here is your effort to fit the Volt into a shoebox of potential uses. Ignoring the fact that many will use the Volt to NOT take 2,000 mile trips 90% of the time. The added ability to take that 2,000 mile trip in your electric car is a luxory above and beyond what other electric cars are currently capable of. It's an ADDED convenience, it is not intended to be the sole use or purpose of the Volt. And in real world use, by the average buyer, it will just be one small sliver of actual use but that doesnt make for a good thread does it?

Could you please provide data that proves your contention that the electric motor wont be in use most of the time for the average user? Of course if your only willing to look at 2,000 mile trips you are right. But what about the guy who is driving the Vlt back and forth to work everyday...maybe his profile would yield different numbers? But that would be meaningless?


I agree with you as well for the usage pattern that Volt probably will be used for, but usage pattern is absolutely critical in that figure, something that GM is not exactly clear on.

In regular cars you get city mileage (worst case scenario) and highway mileage (best case scenario), most people can easily get something in between, no matter their usage pattern. With Volt it's a totally different story, usage pattern is critical, something that is unique to Volt and unconventional, yet GM insists on using a conventional method of calculating fuel mileage in Volt, they should do better, that's all I'm saying.


Frankly, I don't think anyone knows how to properly rate these things for mileage at this point.

Your use would yield one number and mine another. Some will never need gas, some will. The fact of the matter is the car doesnt make sense for many drivers, just as it makes great sense for many others. My only problem is trying to cherry pick a scenario where it makes no sense and claiming other uses and their observed mileage as meaningless.

Meaningfull data and a good buying decision will be based on personal cases from person to person. No one tool does every job everytime, does it? A screwdriver is no good at driving nails. Just like the Prius a smart consumer will do his own math and base his decision on his personal situation. No one at GM ever laid claim to the Volt being the perfect car for everyone that I can recall.

 

[Kestas]

Originally Posted By: Win
Originally Posted By: KrisZ
So while the 127 mpg sounds really impressive, the number is totally meaningless as every one will get something else depending how many miles are covered on battery and how many are covered in range extending mode.

Well duh, thanks for yet another Captain Obvious comment. Wasn't your first round of bashing enough for you?...

I think that comment was unnecessary. There are plenty of people who are myopic and gullible enough (but not the posters here), where Kris's qualifier DOES need to be pointed out.

 

[LS2JSTS]

Originally Posted By: KrisZ
Meantime GM omits an inconvenient truth, that in order to get such mileage you have to recharge the battery about every 50 miles.

GM didn't omit anything. I think everyone involved understands this is a new paradigm. We have to come up with new ways to consider cost and mpg figures...and as we both agree, that will be much more personal going forward. It has to be due to the tech involved and the way it interacts with our daily lives.

Just curious, if you stopped and recharged every 50 miles, what would the MPG number be? Hint, it would be far larger than 127 mpg. The 127 mpg figure was a mixed use number with both ICE and Battery only use. If you ONLY use the battery as you describe above the 127 figure would be miniscule compared to what you would see.

 

[mechanicx]

Originally Posted By: LS2JSTS
"But I still had six gallons of gas left in the tank, which might last me another four months if I continued my usual commuting and weekend driving pattern around L.A., or another four hours if I decided to drive to San Francisco."

Notice the author noted that if driving his normal work commute, the six gallons of gas left in the tank would last him another four months...

I was just thinking with the gas not being used with some drivers and lasting 4 months or indefinitely and with 10% ethanol in fuel that might make for some stale gas lol. It'd probably be a good idea to keep the tank topped up (addds weight though) add Stabil or take the car on a ~400 mile high speed road trip lol. I don't think you can siphon gas out of a late-model tank because of a screen and there's probably no drain plug. I doubt many Volt owners will do any of this but I wonder if the gas lasting so long will be a problem?

 

[Bill in Utah]

Originally Posted By: mechanicx
Originally Posted By: LS2JSTS
"But I still had six gallons of gas left in the tank, which might last me another four months if I continued my usual commuting and weekend driving pattern around L.A., or another four hours if I decided to drive to San Francisco."

Notice the author noted that if driving his normal work commute, the six gallons of gas left in the tank would last him another four months...

I was just thinking with the gas not being used with some drivers and lasting 4 months or indefinitely and with 10% ethanol in fuel that might make for some stale gas lol. It'd probably be a good idea to keep the tank topped up (addds weight though) add Stabil or take the car on a ~400 mile high speed road trip lol. I don't think you can siphon gas out of a late-model tank because of a screen and there's probably no drain plug. I doubt many Volt owners will do any of this but I wonder if the gas lasting so long will be a problem?


EXCELLENT CONCERN! Wonder if the owners manual will have any comments on this (nevermind, we all know how many people READ the manual...)

 

[LS2JSTS]

Good point, and something I've been trying to determine...hard facts are hard to come by at this point. The only comment from GM I've seen thus far....

"“I wish I could talk about it,” he said, “but we will have solutions in place to address the aging-gasoline situation. It’s a great problem to have … [and] the engineers are addressing that situation.” The issue came up long ago during the Volt’s development, Darovitz said.

And some more recent info....

"First, to release the gas nozzle inlet says Berman, the driver must touch a small gas release button on the driver’s door, hard to see, but right above the electric charging door release button.

After pressing the button there is a mandatory wait period signalled on the dashboard screen. During the wait, a vacuum pump decompresses the pressurized tank and pumps vapors into a “carbon canister.” This is a specialized system that normally keeps the gas tank sealed under pressure to prevent seepage of water and other factors that might lead to stale gas.

The car’s computer is always monitoring the gas situation. It knows how long its been since gas was last placed in as well as when the last time the engine was run. It also knows if you open the gas door but don’t actually fill up and even monitors the temperature of the gas to ensure it isnt “cooking.”

The car, of course needs to know all this because after a ceratin period of time the risk of gas going stale increases and the engine needs a cycling.

At that certain point, if fuel hasn’t been burned, the car will display a message encouraging the driver to drive beyond the EV range and let the generator go on. The driver can apparently ignore the warning but after two times the car will “take matters into its own hands,” writes Berman. This means the Volt will start its generator to burn some fuel, lubricate the mechnical parts, and “pressurize the engine system.”

After completing this “engine and fuel maintenance mode,” the gnerator shuts off allowing the car to go back into pure EV operation, until the next time some gas needs to be burned"

 

[brianl703]

Originally Posted By: Bill in Utah

EXCELLENT CONCERN! Wonder if the owners manual will have any comments on this (nevermind, we all know how many people READ the manual...)


This can be solved in software. The computer most likely has a connection to the fuel level sender (pretty standard design these days), therefore it knows when the last time fuel was added. If the time since fuel was last added is too long, it can either alert the driver (who can then top off if doing so will extend the life of the fuel), switch to a gasoline-mode to use the fuel up, or both.

 

[LS2JSTS]

Must have me on iggy....lol

 

[brianl703]

I don't have you on iggy. I'm uncertain if you are referring to my post about the software solution for the stale fuel, but I wrote that before I saw your post.

 

[mechanicx]

That's pretty interesting that they have all those design features to address the gas becoming stale. Also I'd assume the engine needs to be ran ocassionally to prevent corrosion and seals drying out. I think I'd still prefer ethanol free gas in a Volt (really for any car) but it is pretty much non-existant in most places. In a way the Volt will be the ultimate short-commuter as far as the engine and gas is concerned, but it looks like design features are addressing these issues.

 

[LS2JSTS]

Engine/Fuel Maintenance Mode will start the ICE every six weeks to lubricate the engine. Regardless of the age of the fuel in the tank.

Engine/Fuel Maintenance Mode will start the ICE or prompt the owner to drive beyond battery range when the average age of the gas in the tank exceeds a set parameter.

 

[LS2JSTS]

In regard to this issue. Here is a recent blog post by a "claimed" GM Tech, take it for what it's worth....

"Hello- I'm a GM tech who just completed some training on the LUU 1.4l engine that will be in the Volt. to Tom- I asked that same question regarding how much fuel would be burned during a fuel maintenance mode and the answer I got was that the Volt's computer systems calculate the average age of the fuel in the tank, If the average age reaches roughly 1 year, the engine will burn the stale fuel and "prompt a refueling event" in other words, run it out or close to out of gas. That is "Fuel Mantenance" mode. If the engine goes roughly 6 weeks without starting, then it will enter "Engine maintenance mode" and run for about 10 minutes to keep everything lubricated inside the engine. Given that, I wold imagine it to be pretty rare to have the average age of the fuel in the tank be over 1 year. I'm sure all of this is subject to change, but this is how we GM techs were recently taught."

 

[mechanicx]

I think most people won't keep the batteries charged up and will use the IC more than they would have to. My driving cycle could easily go over a year and not use a tank of gas. The fuel maintenance mode of 1 year seems like a long time for gas to be in storage (but apparently the tank is pressurized) as does 6 weeks between engine maintenance mode. But at least GM is addressing the issues, and with it being software easy to update.

 

[JHZR2]

Originally Posted By: KrisZ
In the other Volt thread, another poster said that Motor Trend got 127mpg's from Volt during their testing. I checked their website and they had no explanation on how they got that number at the time.

Well, MT just posted detailed info on that.

http://www.motortrend.com/features/auto_...experience.html


Note that out of 299 mile tip only 84.6 miles were on the IC engine + battery, the rest of the miles were on battery only.

So while the 127mpg sounds really impressive, the number is totally meaningless as every one will get something else depending how many miles are covered on battery and how many are covered in range extending mode.

Also if you calculate that 85.6 miles on IC + Battery used 2.359 gallons of gas, which is 35.8 mpg!, a truly pathetic number for 80% highway commute for a car that is claimed as a “game changer”.

Moral of the story, GM and our pathetic media should provide something more meaningful like mileage in range extending mode on top of battery mileage, as most of the people will take 127, or whatever mileage GM posts, literally and will think you can make over a thousand mile journey in one shot on one tank of gas.



If people take it literally, that's their problem. We have turned off our ability to do math or think logically. It is the consumer's problem if they aren't smart enough to some analysis on their own.

But at the end of the day, it still is game changing and unique. Sorry to the folks who commute more than 80 miles, not my fault/problem... My commute is 9 miles. The volt has what? 30kWh of battery? That is about the same as 3/4 gallon of gas(gross), which has 9.7kwh/L.

However, the rest of the electric drivetrain is 90% efficient, while the gas in the tank will only be worth about 10kwh/gallon after efficiencies are considered.

So the volt battery pack is worth about 3 gal of real fuel put down as rubber on the road. 90 miles...

Difference is Can buy electricity at 15c/kwh, so to charge up would be $4.50.

Meanwhile gas will cost me $7.50 for 3 gal.

Where else can I get a car that will take me a long distance on only electric? Nowhere.

Cost is semi irrelevant as the car is still a prototype in reality, no matter what anyone says, and that means higher per unit costs.

 

[mechanicx]

I roughly figured with gas at about $2.75/gal with my current combined mpg and drive cycle, that recharging the Volt once a night I could do most all a years driving and save about $1500/year on gas. I figure the Volt could have a life expectancy of at least 12-15 years (could be wrong). If the price of this technology goes down, it could easily reach parity with an IC only engined vehicle.

Now of course, I could also buy a less expensive more fuel efficient econobox and didn't really factor in electric cost but I think they would be miminal. On the other hand gas could easily stay above +$3/gal and the Volt seems nicer than most econoboxes. And of course getting off the consumption of gas has other benefits.

With a pure electric car, you are most likely going to need a 2nd car and all the inconvenience of a limited range. Of course batteries are a limiting factor with their limited storage, heavy weight and high cost, so the Volt offers one solution with an IC engine. A pure electric car in many ways could be simpler and maybe even cheaper and more reliable than an IC engined car. If one could just jettison the batteries and all the issues it creates and just draw power from a grid in the roadways somehow, you would have unlimited range without the need for an IC engine. At this point I'm probably showing my ignorance of electrical power transmission, but that would be a neat set up.