How will the Chevrolet Volt be better than a Toyota Prius plug-in hybrid?

It is 290 Wh/mile (29kWh/100mi) for Prius PHV. The new site doesn't allow me to edit my post to fix the typo.

Wanna include how long it takes to refuel 0.2 gallon?

 

Its not that much smaller. Either things were not adjusted or your perception is just highly biased.

Overall passenver volume (from New Plug-in Hybrids)


[pre]
2012 Volt 2012 Toyota Prius
Passenger Volume 90 cu.ft 94 cu.ft
Luggage Volume 18 cu.ft 22 cu.ft
Front Headroom 37.8 in 38.6 in
Rear Headroom 36.0 in 37.6 in
[/pre]


Passenger space Volume Difference about 4%
Front headroom .8" difference or about 2% different (not 2.5 -- the seat must have been raised up)
Read headroom 1.6" difference or about 4.4% different

From Edmunds (2013 Chevrolet Volt Specifications and 2012 Toyota Prius Plug-in Specifications)

 

Nope, the issues with .2 gallons is not about refuling speed, its about the energy the car used. If the test was slow enough that the PiP did not need gas, then the Volt would use less than 360kw/mile.. But without a standard measurement you cannot really say how much less for the Volt or how much more for the PiP. The MPGe (PiP 95, Volt 94) measure the total energy which is similar.

 

John

Link please...

I don't recall any GM spokesperson stating that the MSRP of the Volt would be $30,000. I recall various statements about targeting a price of around that level but it was always ambiguous whether that did or did not include tax credits. Some people chose to assume it was pre-credit.

The current post-credit price is now within $2,000 dollars of that target. Meanwhile, the post-credit PiP pricing also came in above the expectations of many people here by a similar amount.

Unlike the PiP range expectation of 15 miles set by Toyota? And did you (or anyone) really interpret GM's claim to mean the Volt's range would be exactly 40 miles no matter what the conditions were?

Actually, GM characterized the 40 mile range as being based on a specific city-oriented EPA test cycle, not the actual EPA range calculation & test cycle later published by the government.

Toyota likewise used a European test cycle to claim 14 miles of all-electric range but the 15 mile claim used by Toyota in the USA was not specific. The eventual EPA range for PiP was 11 miles (but with a mile worth of gasoline helping out). Ignoring the gasoline used, that is 73% of Toyota's original claim of 15 miles whereas 35 is 88% of GM's original 40 mile claim.

As for 50 mpg (combined rating), this target was originally stated in 2007 when the concept car was rolled out. According to EPA estimation rules at that time, a 2007 Prius got 55 mpg. In 2008, under new rules, the Prius got a combined estimate of 46 mpg. A similar ratio for the Volt target of 50 mpg would shrink it to 42 mpg.

Although the published Volt combined estimate is 37 mpg, I just drove the last 1,200+ miles in mixed city/highway driving using gas only and got around 44.5 mpg measured at the pump. Finally, I was able to fully recharge again last night for the first time in 3 weeks.

You still haven't tried test driving a Volt?

LOL.

Did you try adjusting the seat height or did you just measure it based on whoever adjusted it previously?

I agree that the Prius hatchback design is nicer but according to my own recent measurements the Volt hatchback area is slightly wider and taller than a gen 2 Prius. I recently moved a bunch of standard office-size storage boxes and was able to easily fit 9 of them in the hatchback area with the rear seats folded down.

Probably for the many, many people who are of somewhat above average size or smaller and rarely need five seats. Just my guess...

 

If you want to discuss about the energy used, include the fuel production as well. EPA figures do not include upstream loss. Electricity has much greater loss (66% vs 15%) than gasoline, on average. That begs the question if the over-sized plugin battery and motor are worth it, to power higher EV speed, incapacitate gas engine and increase refueling time.

 

The concept was shown as under $30k and tax credit did not exist back then. 40 miles EV and 50 MPG with 1.0 liter AT-PZEV gas engine.

The production version came out looking totally different after going through the wind tunnel. The gas engine was changed to 1.4L ULEV (not even SULEV). 50 MPG goal was downplayed as CAFE MPG (Prius gets over 71 CAFE MPG). AT-PZEV model was introduced 2 years later (not available in all states).

Volt was shown as a Chevy, in order to target the middle market to enable mass production. With every target missed, Volt didn't turn out as planned.

The important part is that it came out and if it survives through the next generation, there are a lot needed to improve - more than Prius GenI -> GenII.

 

It's been the same old game ever since Two-Mode was first conceived. GM says something vague & ambiguous, then allows hope to build without clarifying incorrect expectations. Then the executive who made the comment moves on, allowing hype to propagate without recourse in blogs & forums. The most recent example is the mention of a plug-in Equinox. Who knows what will become of that. But without accountability, you're fighting an idea, not a promise or actual goal.

To complicate matters, people forget what happened when. That makes it really easy to be misled, simply by missing vital pieces of detail.

That's why it boils down to sales. The debates about expectations are over.

 

Comparing to HS250h is unfair. Not only nominal power is higher in HS (184hp vs 150hp of Volt) but HS is much bigger (giving Cd.A higher).

If in technical terms you modellate HSD power paths and a Atkinson ICE, and compare to Voltec II+Otto, overall efficiency is much lower in the latter. Questioning that somehow seems a bit surprising...

 

Sure, lets discuss total energy used. I pay for 100% renewable.. so my upstream loss, in terms of fossil fuel wasted, is < 15%.

Average has no significance in how to measure what I do.. just like average vehicle MPG does not apply.
A bigger battery gives on the choice of where to purchase most of the fuel. A small batter is better than none, but still with a smal battery one still depends mostly on gasoline

 

Actually the HS250 is NOT much larger.. it has 90 cu.ft of passenger volume, the volt has 90 cu.ft of passenger volume. HS250 is 70" wide, the Volt is 70" wide The HS250h hs is 59" tall, the Volt is 57". ​

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Most significantly given your arguments, , HS250 coefficient of drag .27 is 7.4% lower than the Volt @ .29. ​

So your arguments on size/drag are incorrect. ​

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Nominal power should not make a significant difference given the driving profile for EPA testing is exactly the same. They are not supposed to accelerate any faster the the predefined profile. (Admittedly the higher HP gives an agressive driver more opportunity to waste gas and be well under EPA). In addition, despite the HP difference, the Volt and HS250 have similar 0-60 times. ​

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If just combining Atkinson and HSD where that much better, then why is the HS250 getting less MPG_CS than the Volt? ​

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Where do you get that "100% renewable" electricity? Unless you have a wind turbine in your backyard, you are getting your electricity from the grid. Therefore, you ought to use the grid average, IMHO.

Gasoline fuel production and transportation loss is about 15%. That's the average of all the refineries and locations of every gas stations. There is no point in claiming greener by living closer to the oil well or refinery since you don't have much fuel transportation loss. The same goes for paying extra for renewable electricity while the night time electricity used to recharge comes from coal power plants. Just use the average grid electricity, KISS.

Average MPG of all the cars is irreverent to an individual gas car the same way the average kWh/100 miles is irreverent to an individual EV.

The bottom line, vehicle efficiency can apply to individuals but fuel production efficiency is best to use the average.

Regarding the battery size, there is a point of diminishing return. Volt is well past that. The SUV weight, compact 4 seater interior volume, premium gas requirement, 37 MPG, composite 60 MPGe, retail price, etc. These are the results (direct or indirect) of having an oversized plugin hybrid battery.

 

Well, let's see. 2.4 liter vs 1.4 liter ICE. HS250h ICE is outdated as well. See the ES300h or Camry hybrid with the modern 2.5 liter engine. They get 39-40 MPG on regular gas from a midsize delivering ~200hp.

 

Electrons are inherently fungible. Your welcome to your uninformed opinion, but that does not make it correct. The point of Renewable Energy Credits is exactly to allow people to purchase energy and insure that such customers get what they pay for. Each REC credit has a unique code and can only be "used" once, so i know I've paid for wind-based energy that no-one else can also claim they used/paid for. I also know that the REC credits paid to our local co-op even led to local capacity installation. Every kWh of power I pay for can be traced back to wind-based generation. Colorado has a surplus of wind, especially at night.

If you want a small one, that is your choice. For me the Volt's pack is nearly ideal in size. When there are PiP's doing 400MPG over thousands of miles, maybe you'll arguments will have some validity. For now, even for those with a more PiP ideal drive pattern, real-world data is showing that PiP's battery is just too small.

 

The answer is rather obvious, HSD and atkinson will not all by themselves make a car more efficient.

First lets look at atkinson, which is rather an technique for increased native compression and late valve closing to gain efficiency. All things being equal, in a hybrid or phev this will make it more efficient. But things are not equal, the Atkinson engine in the hs250 is a less efficient design than say the one in hybrid camry or upcoming or ford fusion. The multimode valve timing of mazda's skyactiv or di+turbocharging of the ecoboost are also ways o improve efficiency. Both the engine in the volt and the hs250 could be made more efficient I expect a more efficient engine in the gen II, whether it uses atkinson or not. The concept car though did have something more like the ford 1L ecoboost, though I doubt this will be what is in the next generation. GM stated that they used the 1.4L engine because they did not take the time and money to develop a better one, but it is one area we can expect improvement. The current engine is not bad by any means and is more efficient than most ices out there. The bulk of the efficiency differences are the ice and the one in the volt is less efficient than the one in the prius, but more efficient than the hs250.

Whether HSD is better than voltec depends on driving conditions. In Electric mode the voltec should be more efficient as there are less frictional losses. At low speeds say less than 10 mph they should be about the same, as the hsd primarily is moving through mg2. At high speeds when the engine is engaged to the wheels through the clutch they should also be similar. During most speeds though the hsd will have less conversion losses, although when this is all added up, it should not be a high percentage, likely around 10%. The tradeoff is in those times the voltec is less efficient than the hsd, it will still accelerate the same way as it would in electric mode, since it is in electric mode. Whether this driving feel is worth the efficiency hit depends on both what percentage of time the car is in this mode, and how much driving feel maters. I'm sure the naysayers would also complain about 41mpg combined in cs mode, just as much as they complain about 37mpg, and I doubt the difference is this much.

 

So to get apples to apples, the energy used by the PiP is 29kwh/100mi plus .2 gallons/100 mi. Using the EPAs conversion of 33kwh/gallon you get 29kwh plus .2*33 or about 35.6kwh/100 miles.

 

Zythryn - More like half-apple to half-apple comparison. Apple to Apple comparison would also include fuel production as well as vehicle efficiency. Plugin hybrids use two fuels so the tricky part is to use the right fuel at the right time to minimize carbon footprint beyond the tailpipe. If you want to game the EPA's MPGe rating, you would want a plugin that uses as much electricity as possible. But, is it good for the environment? Nope. We need to look at the entire well-to-tank-to-wheel (fuel production + vehicle efficiency).

@Dr.I - I am not saying Prius PHV is a better car for you. I am just pointing out the advantages and disadvantages. With bigger battery, comes longer recharge time and more electricity. It seems, Volt is a better fit for you as the advantages of the Prius PHV have no use for you.

I understand the fungible view of electron, like money in bank account. The problem with that view is that we have the concept of dirty electricity vs clean electricity. We value the electrons from a clean energy source more. We don't have such differences in value for the money. A dollar from the church is worth the same as a dollar from the drug dealer. Therefore, electrons are fungible but the electricity is not.

 

You are arguing that the PHV is better.. it is for some, but not for others. WIth real-world data Volt users are using less gas.

Electricity is always clean, its the sources that are used to generate it that can be clean or dirty. If I just buy without regard to source, the average makes sense. If I purchase from a particular type of source, then i get to choose. And at least some of us do view money as having sources and sinks that effect our view of it. I'd rather my money to local companies than international oil conglomerates and OPEC. I also prefer to purchase locally grown foods, even if tomatos are tomatos.

Here is a nice document on green energy and how it works.

 

Here's another real world drive efficiency data point.

I did a full charge overnight. Drove to work on the expressway at 50 mph with occasional stops at intersections. Drove back home on highway at 55-60 mph. Drove to San Francisco with a 1 hour and 19 minutes charging stopover in South San Francisco all on battery.

Free parking and charging at 3.1 kW for a calculated total of around 4 kWh while I relaxed at Peet's Coffee and sipped my obligatory hybrid driver soy latte.

Continued my trip to SF and arrived at my destination on all battery power. Did my tasks and errands but was unable to charge. Drove back home on highway 55-60 mph on gas except for the first 2-3 miles.

So, mostly expressway and highway but with 7-8 miles of city driving including some hills in SF.

Final stats:

58.1 battery miles
17.5 kWh estimated (300 Wh per mile) wall-to-wheel

36.3 gas miles
.77 gallons (47 mpg)

94.4 total miles
123 total mpg

 

The difference between 95 and 94mpge isn't a lot faster consumption. It's only a little more that can just be a 0.1 rounding difference. Or are we ignoring the Prius' gas consumption in EV mode for this comparison.

Why continually bring up total charge times when the majority of times a person will be fully charging is while at home sleeping? For opportunity charging, they are both getting near the same miles per charge time. In any case, it isn't like refueling with gasoline, where you have to be near the pump, in the weather.

The Prius' shorter time to full charge on a smaller battery might be an advantage for charging at work, but it depends on trip length. That's assuming work charging is possible. I can't. I'd have to run 100ft + of cord over sidewalks and pavement to the nearest outlet. I can think of only one job I've had where an outlet could have been convenient, and then the cord would still be running over a sidewalk. Let's be honest, anytime a cord is lying on a public walkway is asking for a lawsuit. So I think most people won't have the opportunety to charge at work.

 

Let's take your analogy just one step farther. If everyone spends their dollars on churches and none on drug dealers, what will be the result in 10 years. You know the answer and how it relates to electron sources 10 years down the road.