Chevy Volt: A lot of unanswered questions

[AVANTI R5]

Performance, price, and value - there's still a lot of gray area around GM's electric car

NEW YORK (Fortune) -- While General Motors continues to define itself post-bankruptcy, it is pushing ahead with one of its key pre-bankruptcy projects: developing the Chevy Volt.

This week, a team of GM vehicle engineers is testing eight battery-powered Volts on a three-day, 1,200-mile drive from southeast Michigan to Pittsburgh.

The engineers will evaluate everything from the sound system to the seats, but most of their attention will be focused on how the Volt performs under electric and gasoline power.

Lots of questions remain, as I discovered when few a words about the Volt at the end of my last column drew a number of heated responses.

My comments focused on speculation about the performance of the Volt after the batteries discharge and the range-extending gasoline engine kicks in.

Sine the Volt weighs close to 4,000 pounds, according to a knowledgeable source, and the engine only displaces 1.4 liters, some have guessed the Volt would be a slacker under gasoline power.

"Absolutely incorrect," says a GM spokesperson. "There is no degradation in the Volt's performance after the battery has reached its lower state of charge. The engine-generator provides sufficient power to propel the vehicle."
GM says that the Volt will be able to accelerate from zero to 60 miles per hour in 8.5 to 9 seconds, whether it is running on battery or engine-generator power.


That's not all. Also under scrutiny is GM's oft-repeated assertion that the Volt will have an all-electric range of 40 miles. Critics point out that the car needs ideal conditions to do that.

For one thing, the 40-mile range depends on ambient temperatures of 60 degrees to 65 degrees. When the temperature drops below 60, the batteries become less efficient. And if it gets hotter than 65, the air conditioner can impose an additional load on the Volt's batteries. Either way, the range diminishes.

Nor does the 40-mile range accommodate aggressive driving or sustained uphill climbs -- you don't have to be a budding drag racer or hill-climb contestant to get less than the full range on electricity.

Other questions about the Volt are almost philosophical: Just what is GM is trying to achieve with the Volt, and how much value does it provide the customer?

For instance, compare the Volt to the best selling gasoline-electric hybrid, the Toyota Prius. The goal of the Prius is to use less gasoline. Therefore, it carries 230 lbs of batteries that give an assist to the 1.8 liter gasoline engine to improve the car's fuel economy. The Prius has an all-electric range of only about a mile, but it gets 50 miles per gallon of gasoline.

And oh yes, the Prius starting price is $23,750.
The Volt, in contrast, wants to almost entirely do away with gasoline. Therefore, it carries a hefty 400 pounds of batteries that can propel the car up to 40 miles under ideal conditions. But once the batteries have been depleted, the Volt is powered by a conventional 1.4-liter gasoline engine that gets conventional fuel economy.

And the price for the Volt hasn't been set yet, but it will likely be a tad under $40,000, minus a $7,500 government rebate -- a good bit higher than the Prius.

So here's one way to look at: The Volt will be easier on the environment, but only if you don't mind paying a premium and drive fewer than 40 miles per day.

The Prius weighs more heavily on the environment but performs consistently under nearly all conditions and cost less.

Choosing between the two will be up to customers, beginning at the end of 2010 when Volt is scheduled to go on sale.

http://money.cnn.com/2009/10/15/auto...on=money_autos

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[bheinen74]

the Volt will never be built or sold to public.
Volt is DEAD, Fail, etc.
next.

[justincredible]

I had already forgotten about the Volt.

By the time it hits showrooms it'll be years out of date.

[SLegacy99]

I'm thinking that a 1.4L spinning at optimal RPMs will do well.

The initial Volt was supposed to AWD. Have we heard anything about the powertrain. Im just assuming that since I havent, it's FWD.

[sxotty]

Originally Posted by bheinen74

the Volt will never be built or sold to public.
Volt is DEAD, Fail, etc.
next.

They already built 80 so I guess you are wrong on the first point.

Once again a journalist exposes their ignorance. Once again people give them attention for it. Fact checking is apparently too old school for them now days. Instead a bit of controversy gets them revenue so just write down some lies and hope that it goes well.

[Mechie3]

Who uses air conditioning at 65 degrees?

[linus011]

I saw a volt in light camo going down 275 here in Livonia.

[scott_gunn]

But once the batteries have been depleted, the Volt is powered by a conventional 1.4-liter gasoline engine that gets conventional fuel economy.

That part is wrong. It will still get exceptional fuel economy due to the electric drivetrain and the engine running at a constant, optimal RPM.

[sxotty]

Originally Posted by scott_gunn

That part is wrong. It will still get exceptional fuel economy due to the electric drivetrain and the engine running at a constant, optimal RPM.

More importantly it will still do regen and all just like a prius. Depending on peoples commute you can gain up to 30% energy back from regen. The EPA drive cycle they test gains about 8% back on regen. With a conventional vehicle you make heat in your brakes and wear out your brake pads. The most annoying thing is that he says 40 miles is best case. That is just stupid.


It isn't even close to best case. I guarantee people will be able to get 80 miles on a charge if they are being all silly and trying to hypermile.

[Chromer]

Apparently if you have a Master's degree in journalism it allows you to speculate instead of fact-check...

Granted, GM isn't saying much on certain questions right now, so speculation is all we can do. Still, apparently this guy just isn't getting the concept behind a serial hybrid with a big battery and is basing his assumptions around how the Prius behaves with a low battery (which isn't good, trust me).

So shooting just one hole in this guy's suppositions... Let's say GM makes the gas engine come on at 30% charge level in the battery* (indications are that this is the case). We know it's a 16kWh battery, which means there is 4.8kWh left. We also know the electric motor is around 100kW and the generator puts out 53kW. Go full throttle as soon as the gas engine kicks on, you'll be drawing 53kW from the generator and 47kW from the battery. It'll take just over six minutes (4.8kWh/47kW = .102 hours) to pull the battery down to 0% charge, 4 minutes if they limit to 10% SOC to protect the battery... How many roads are there in the US where you can hold the accelerator flat for four minutes? (Well, Montana in the good old days, but lets be realistic...) As soon as you let off the throttle, the excess power from the 53kW the generator puts out will go back into the battery until the charge level gets to the engine shutoff point (40% SOC? Nobody outside GM knows yet). Remember that cruising 65 on flat ground in this small, aerodynamic car will probably only need about 10kW of power - and that means lots of excess generator capacity to keep the battery in it's happy place under realistic driving conditions, and no loss of power except on the longest grades at high speeds.


I, for one, welcome our electrically-powered overlords, and as a media figure I can be useful in helping convince others to work in your electron mines...


*All specifications from gm-volt.com

[tacomaprime]

Originally Posted by justincredible

I had already forgotten about the Volt.

By the time it hits showrooms it'll be years out of date.

You talking about the volt, or the new camaro?

[Chromer]

Originally Posted by sxotty

It isn't even close to best case. I guarantee people will be able to get 80 miles on a charge if they are being all silly and trying to hypermile.

FYI, hypermiling doesn't work so well in electric-driven vehicles... In a gas motor you have efficiencies from about 5% up to about 35% depending on RPM and load. Traditional hypermiling tries to maximize the time spent in the high efficiency range (high throttle opening + closed-loop fuelling + low RPM's) and minimize time in low-efficiency range (high rpms, open-loop fueling and low-throttle-opening+low-load).

With electric motors, the efficiency curve is VERY different, and efficiencies range from the mid-70% up to the high 90% level... Pulse and glide should not be nearly as effective as in a gasser.

[Hawk296]

Originally Posted by linus011

I saw a volt in light camo going down 275 here in Livonia.

And I saw one with light camo on M59 by the airport.

[sgilson]

I've stopped listening to the naysayers. The factory were the Volt will be built is being put together as we speak. From what I understand, they will build around 3000 units next year and over 60000 units the following year. Fail? Probably not. Too many people will buy these things and I'm one of them. If this was a Toyota there would be more praise going around. Also with Chevy confirming the Convertible Camaro will go on sale as a 2011 model and the Z28 all but confirmed, I'll have an all American stable. The camaro5 forum has been debating the lineage of the Z28 for a couple of months now and sound like they want different model Camaros to suite different engines. I'm all for the CTS-V motor, but I wouldn't mind having the LS7 either. Something makes me all tingley hanging that 427 on the side of my convertible Camaro.

[SLegacy99]

Originally Posted by sxotty

More importantly it will still do regen and all just like a prius. Depending on peoples commute you can gain up to 30% energy back from regen. The EPA drive cycle they test gains about 8% back on regen. With a conventional vehicle you make heat in your brakes and wear out your brake pads. The most annoying thing is that he says 40 miles is best case. That is just stupid.

Well exactly. GM doesn't call it a hybrid, but the Volt will act as one when its not running on pure electric.

Originally Posted by sgilson

I've stopped listening to the naysayers. The factory were the Volt will be built is being put together as we speak. From what I understand, they will build around 3000 units next year and over 60000 units the following year.

Question is, will EV1 loyalists buy em? I am willing to be GM poed enough EV1 Leasees. that they would never buy another GM.

[sxotty]

Originally Posted by Chromer

FYI, hypermiling doesn't work so well in electric-driven vehicles... In a gas motor you have efficiencies from about 5% up to about 35% depending on RPM and load. Traditional hypermiling tries to maximize the time spent in the high efficiency range (high throttle opening + closed-loop fuelling + low RPM's) and minimize time in low-efficiency range (high rpms, open-loop fueling and low-throttle-opening+low-load).

With electric motors, the efficiency curve is VERY different, and efficiencies range from the mid-70% up to the high 90% level... Pulse and glide should not be nearly as effective as in a gasser.

Just look at the mileage people get in a prius though. Or a PHEV converted prius. If you look at the hypermillers they get ridiculous numbers, but they drive like snails or tail gate or do all sorts of stupid annoying stuff.

[SCRAPPYDO]

Why should my tax dollars go give incentives for this car. Its bad enough they already have 50 billion bucks from us. At 32500 it better have stellar quality and reliability. If they are going to produce 60000 of these a year, then they are going to be quite a few sitting in lots unless they are drastically reduced.

[sxotty]

Originally Posted by SCRAPPYDO

Why should my tax dollars go give incentives for this car. Its bad enough they already have 50 billion bucks from us. At 32500 it better have stellar quality and reliability. If they are going to produce 60000 of these a year, then they are going to be quite a few sitting in lots unless they are drastically reduced.

We have gone over this repeatedly. You spam the same thing every time. Someone patiently explains to you the economics involved and how such a subsidy can make sense then you spam it again. Quit posting it as a question at least. Obviously you start with "Why" and end with a period so you do not really want an answer you just want to complain.

[SCRAPPYDO]

Yeah, for the most part, I am just complaining. But on the other hand nobody has explained it in a way it MAKES SENSE. So I will continue to complain about it. The government owns GM. The government giving tax payer dollars as incentives to sell a car they own is a bit shady.

I have gone over this repeatedly. And yet, when I patiently explain it people still do not understand. Guess I have not explained it so it MAKES SENSE either.

[Not-EWRX]

I thought this was supposed to be here by now?

[boxerinside]

40 miles?!!!!


400lbs just for battery weight!
no wonder these companies are dying.

[Balantz]

Originally Posted by boxerinside

40 miles?!!!!


400lbs just for battery weight!
no wonder these companies are dying.

You obviously know zilch about the technology or the realities of most people's driving needs. Battery power to weight ratio has improved dramatically in the last 12 years since GM made the EV1. In that car, the battery pack weighed 1,200 pounds and produced significantly less power. Additionally, do you drive more than 40 miles a day? Most people do not.

I'm no fan of GM, but let's be clear about the facts, shall we?

[sxotty]

Originally Posted by Not-EWRX

I thought this was supposed to be here by now?

It has always been scheduled for 2010. And that means probably nov-dec so more than a year away. I would rather have a tesla roadster, but they are a tad expensive

[sxotty]

Originally Posted by SCRAPPYDO

Yeah, for the most part, I am just complaining. But on the other hand nobody has explained it in a way it MAKES SENSE. So I will continue to complain about it. The government owns GM. The government giving tax payer dollars as incentives to sell a car they own is a bit shady.

I have gone over this repeatedly. And yet, when I patiently explain it people still do not understand. Guess I have not explained it so it MAKES SENSE either.

It doesn't make sense b/c you are are not dealing with facts. The government is not giving money to people who buy volts. They are giving money to people that buy PHEVs with >4kWh batteries and <16kWh batteries. That is who they are giving it to. It doesn't matter who manufacturers them. That is a fact. Get that into your head then try asking your question again. Honda will have one, Nissan will have one, Toyota will have one. Ford will likely get one soon. So don't worry yourself overly much about GM getting the money. And if the IPO is successful anytime soon then the government will get out of GM.

[SLegacy99]

Originally Posted by Balantz

You obviously know zilch about the technology or the realities of most people's driving needs. Battery power to weight ratio has improved dramatically in the last 12 years since GM made the EV1. In that car, the battery pack weighed 1,200 pounds and produced significantly less power. Additionally, do you drive more than 40 miles a day? Most people do not.

I'm no fan of GM, but let's be clear about the facts, shall we?

My commute isn't 40 miles. But it will soon be about 100 a day. 40 on electric and then the other 60 as hybrid with a small, efficient engine would be pretty nice.

I predict that 40 miles in a conservative estimate. Think of the Prius originally had 60 MPG rating. Most people got around 50 and then complained to Toyota that they weren't getting what they should. GM knows this. Thus, it is smart to be conservative and then reap the benefits of happy customers who rave about exceeding the rating. I do it with our 400h. Word of mouth works.