Film-Tech Forum ARCHIVE: Ridiculous Gas Milage Claims by GM for Chevy Volt

my profile | my password | search | faq & rules | forum home

»	Film-Tech Forum ARCHIVE » Community » Film-Yak » Ridiculous Gas Milage Claims by GM for Chevy Volt (Page 1)

This topic comprises 2 pages: 1 2

Author

Topic: Ridiculous Gas Milage Claims by GM for Chevy Volt

Lyle Romer
Phenomenal Film Handler

Posts: 1400
From: Davie, FL, USA
Registered: May 2002

posted 08-11-2009 08:26 AM

So GM has announced that the Volt will get rated at 230 MPG city based on early testing. Both them (and the EPA) need to come up with a new way to specify "Extended Range Electric" vehicles so they can be compared to regular vehicles.

You can't just count the 40 miles it can go with no gas in the calculation because that 40 miles ran on electric that came from somewhere. They need to somehow calculate the electricity used from the grid in the equation.

If you buy a Volt and only drive 30 miles a day you're not getting infinite fuel efficiency, you're just using "fuel" from the power plant instead of the gas pump.

| IP: Logged

Chris Slycord
Film God

Posts: 2986
From: 퍼항시, 경상푹도, South Korea
Registered: Mar 2007

posted 08-11-2009 09:11 AM

Except that would be an arbitrary number because the amount of traditional fuel used to create electricity is in no way the same across the board. If you use a company that only provides taken from renewable resources, then you are in fact getting "infinite mileage."

And using the amount of gas used in the power plant will only confuse people. People expect the same metric to be used comparing different cars. If the car was given a 50 MPG rating, someone would say "What's the big deal?! I'll use just as much gas anyway as a new Prius." and not realize that they will absolutely not.

And part of the reason for mentioning gas mileage is to point out how much pollution you'll create. Now before you say "But you'll still be using some fuel created at a power plant and that'll have pollution" you're forgetting that it's TONS easier to reduce pollution from a handful of individual plants than it is to do so in tons of individual cars, so if you are implying that this won't reduce pollution because we'll still use fuel, it's simply not true.

| IP: Logged

Lyle Romer
Phenomenal Film Handler

Posts: 1400
From: Davie, FL, USA
Registered: May 2002

posted 08-11-2009 09:58 AM

What I'm saying is that it isn't a valid comparison to calculate MPG starting with a fully charged battery in a plug-in hybrid.

A Chevy Volt will not create 1/5 the emissions and use 1/5 the energy of a Prius for example.

If you're looking at the cost analysis, you can't say "I'm going to get 230 MPG therefore I'll save $5,000 a year in gas" because you have to spend money on the electric.

| IP: Logged

Chris Slycord
Film God

Posts: 2986
From: 퍼항시, 경상푹도, South Korea
Registered: Mar 2007

posted 08-11-2009 10:36 AM

quote: Lyle Romer
What I'm saying is that it isn't a valid comparison to calculate MPG starting with a fully charged battery in a plug-in hybrid.

I don't see why. Most people who buy the car will use it and charge it at night, so the most common usage scenario will be someone having a charged car. Ignoring that in the calculation doesn't make a bit of sense. That's like saying that we should only measure the MPG of a Prius when the part that doesn't run the engine is automatically cut off... which ignores that people don't run Prius's with the battery removed.

quote: Lyle Romer
A Chevy Volt will not create 1/5 the emissions and use 1/5 the energy of a Prius for example.

The most common usage scenario will be you driving to and from work, school, etc. And since all of those things are within a relatively short distance to me, I would not only have more than 1/5 less emissions I would have no emissions at all. Now perhaps others out there live further away from their work/school than I do, but I'm pretty sure that most people drive less than 40 miles in a day.

quote: Lyle Romer
If you're looking at the cost analysis, you can't say "I'm going to get 230 MPG therefore I'll save $5,000 a year in gas" because you have to spend money on the electric.

Who said you could? And you're ignoring that people aren't just looking at this as a cost analysis. A lot of people out there simply want to use less gas for that whole pollution thing. And even if you consider that gas might still be used to make that electricity, we're ignoring that converting gas into electricity is actually a more streamlined process than using it to combust and convert that into piston motion. And once we have electricity stored, we have much more efficient electric motors than combustion ones. So you could still end up both saving money (by using less overall energy) and having less emissions.

| IP: Logged

Joe Tommassello
Jedi Master Film Handler

Posts: 547
From: Coatesville, PA, USA
Registered: Jan 2008

posted 08-11-2009 11:18 AM

Government Motors needs all the good press it can get and 230 MPG is pretty impressive sounding. The real question is what does it get in MPG if there is no charge on the battery and you are driving it start to finish using gas. I rented a Prius once and was getting - assuming the on-board computer was calculating correctly - 50 MPG on my typical drive to work (60-65 miles EACH way). If the Volt does that and has the added benefit of getting the first 40 miles without using gas that would be a good combination.

On the other hand Chris...as far as being a "cleaner" product we would need to consider the fuel burned to create the electricity that charges the battery. Didn't Penn and Teller do a show on that? Not saying it would be worse...just mentioning it has to be considered.

| IP: Logged

Chris Slycord
Film God

Posts: 2986
From: 퍼항시, 경상푹도, South Korea
Registered: Mar 2007

posted 08-11-2009 11:39 AM

quote: Joe Tommassello
On the other hand Chris...as far as being a "cleaner" product we would need to consider the fuel burned to create the electricity that charges the battery. Didn't Penn and Teller do a show on that? Not saying it would be worse...just mentioning it has to be considered.

And I explained that already.

Lets assume both gasoline cars and using them on the grid produce equal amounts of pollution. Even in this case, it is better to put them on the grid. Why? Because it is easier to fix the problems in one power plant that provides the electricity for an area than it is to fix the cars of all drivers in an area.

And again, in reality, gasoline combustion power plants are designed quite a bit differently from regular car engines and are significantly more efficient and with lower emissions for the amount of energy created.

| IP: Logged

Lyle Romer
Phenomenal Film Handler

Posts: 1400
From: Davie, FL, USA
Registered: May 2002

posted 08-11-2009 11:54 AM

The one issue with the argument about electric cars being cleaner/more efficient by default because of the central generation is that there are losses in the proccess.

A modern gasoline ICE turns around 22% of the available energy in the gasoline into useable energy. Power plants are somewhere in the 35%-55% range depending on design and fuel. Obviously newer plants are more efficient. But....there are transmission line losses, losses in the battery charging process and losses in the electric motors.

I don't have time to dig up values for all those losses right now but when you take everything into account you will end up a lot closer to gasoline ICE efficiency than you'd think.

Granted, it will be better but then you have to start looking at the energy to produce and recycle the batteries and whatever hazardous wasted is involved in those processes.

| IP: Logged

Sam Graham
AKA: "The Evil Sam Graham". Wackiness ensues.

Posts: 1431
From: Waukee, IA
Registered: Dec 2004

posted 08-11-2009 12:25 PM

For those of us who are more interested in real word cost per mile, I will quote Auto Week's article:

Full article

quote: Auto Week, which isn't really weekly anymore
At the U.S. average cost of electricity (approximately 11 cents per kWh), a typical Volt driver would pay about $2.75 for electricity to travel 100 miles, or less than 3 cents per mile.

Compare that to, say, 40mpg at $2.50 per gallon, you're looking at $.08 per mile. Under that scenario, it would take 80mpg on pure gas to equal the electric number, or for gas to be in the $1.20-$1.30 range, to equal the cost savings of pure electric.

| IP: Logged

Mike Blakesley
Film God

Posts: 12767
From: Forsyth, Montana
Registered: Jun 99

posted 08-11-2009 01:25 PM

Has anyone ever considered all the emissions and etc. necessary to produce the batteries for electric cars? How does that figure in to the "carbon footprint" reduction from not burning as much gas?

| IP: Logged

Joshua Waaland
Jedi Master Film Handler

Posts: 800
From: Cleveland, Ohio
Registered: Dec 1999

posted 08-11-2009 01:48 PM

I have an F250 crew cab pick-up which gets about 11mpg and I don't plan to switch to a fuel efficient car anytime soon. I love my big truck and they will have to pry it from my cold dead hands to get me to drive one of those miniature, death trap, tree hugger cars. [Big Grin]

| IP: Logged

Lyle Romer
Phenomenal Film Handler

Posts: 1400
From: Davie, FL, USA
Registered: May 2002

posted 08-11-2009 01:56 PM

quote: Sam Graham
Compare that to, say, 40mpg at $2.50 per gallon, you're looking at $.08 per mile. Under that scenario, it would take 80mpg on pure gas to equal the electric number, or for gas to be in the $1.20-$1.30 range, to equal the cost savings of pure electric.

Part of that savings is because you're not paying gas taxes. I've heard a lot of chatter about going to a mileage tax instead of gas tax due to more efficient cars. Since gas tax money is used (supposedly) for road construction and maintenance they will need a way for Volt drivers to pay their fair share. Taking that into account doesn't make the cost equal but it gets closer.

I'm not anti-electric car I just think fair comparisons should be made. My wife drives a Ford Escape Hybrid and she averages 34 MPG combined. I can't compare that to a Volt in efficiency because of the Volt's plug-in ability.

| IP: Logged

Charles Greenlee
Jedi Master Film Handler

Posts: 801
From: Savannah, Ga, U.S.
Registered: Jun 2006

posted 08-11-2009 05:00 PM

quote: Lyle Romer
A modern gasoline ICE turns around 22% of the available energy in the gasoline into useable energy. Power plants are somewhere in the 35%-55% range depending on design and fuel.

I think that's measured right out of the plant. If I remember corretly, around 70% of that power is lost over the transmission lines and equipment. So in the end, less than 30% of power generated at the plant actually makes it to your home. So, to determine overall efficeincy, take an optimistic 30% from the starting, we'll be generous, 55%. So at the outlet, you only really see a useful 16.5% of energy compared to fuel used to create it at point of origin. And finally, you'd have to additionally count in the efficiency of the car to get a grasp on total efficiency. But even before that, the 22% of the ICE is greater than the resulting 16.5% grid power.

I've had some decently long conversations with one of my buddies that works as an engineer for the electric company. He said that it's a shame, in a way, working for a company who loses 70% of it's product before it even gets to the consumer.

Plug in cars are just passing the carbon footprint buck, and to a less effecient source at that. Of course, if there were more renewable resource plants, then even that 16.5% is preferred to burning long chain hydrocarbons.

| IP: Logged

David Stambaugh
Film God

Posts: 4021
From: Eugene, Oregon
Registered: Jan 2002

posted 08-11-2009 06:43 PM

Nissan Leaf: 367 MPG

quote:
“Nissan Leaf = 367 mpg, no tailpipe, and no gas required. Oh yeah, and it’ll be affordable too,” the folks over at Nissan’s electric vehicle Twitter feed wrote today. About an hour later, they added this statement: “To clarify our previous tweet, the DOE formula estimates 367 mpg for Nissan Leaf.”

| IP: Logged

Joe Redifer
You need a beating today

Posts: 12859
From: Denver, Colorado
Registered: May 99

posted 08-11-2009 07:01 PM

If it has no gas, then it does not need an MPG rating since there are no gallons of gas to measure.

| IP: Logged

Monte L Fullmer
Film God

Posts: 8367
From: Nampa, Idaho, USA
Registered: Nov 2004

posted 08-11-2009 07:26 PM

quote: Joshua Waaland
those miniature, death trap, tree hugger cars.

(..lol..I've been driving them since I got out of high school over 40 yrs agao... and I ain't dead yet. Cars and motorcycles can't kill people..people kill people..)

And the thing is - the price for a VOLT: close to $40k .. NOW, who's gonna shell out that kind of dough to save mileage (unless Gov't Motors can give us a $25K "cash for clunkers" rebate to get us in one of them things...)..This really doesn't make any sense to spend mega bucks to save pennies.

It's a "thanks, but no thanks" sort of deal. I'll keep driving my 35mpg, "tree hugger" vehicle.

-Monte

| IP: Logged

All times are Central (GMT -6:00)

This topic comprises 2 pages: 1 2

Printer-friendly view of this topic

The Film-Tech Forums are designed for various members related to the cinema industry to express their opinions, viewpoints and testimonials on various products, services and events based upon speculation, personal knowledge and factual information through use, therefore all views represented here allow no liability upon the publishers of this web site and the owners of said views assume no liability for any ill will resulting from these postings. The posts made here are for educational as well as entertainment purposes and as such anyone viewing this portion of the website must accept these views as statements of the author of that opinion and agrees to release the authors from any and all liability.