Prius Plug-in vs Chevy-Volt thoughts

This is easy to find for the concept -

When they first announced production the two big changes were the shape to be aerodynamic, and the engine to reduce development costs. At the time they announced the engine change it was also thought the market might not want a 3 cylinder engine in an expensive car, and the 4 cylinder 1.4 was to be di. The di was dropped to reduce cost on the cruze. Ford now builds a 3cylinder ecoboost exactly like gm thought up in the volt concept, but we would not expect that gm wants to buy engines from ford, or mazda 1.4L skyactiv, or nissans 1.2L miller 3cyl or any competition that has engines closer to the concept. This does not mean they can not do an Atkinson or a turbo in gen 2.

Until the last minute it was expected that the 1.4L would be flex fuel like the original. Nice concept of dual tanks to hold gas and e85, and allow driver to decide what burns. Ford now has combined injection engines to increase e85 at higher boost.

Note diesel was talked about as a nod to those pushing maximum mpg without regard to pollution. This was a continuation of the pngv ideal, which had goals that would not produce a car within the epa legal limits of NOx. GM now has the clean diesel tech to meet the epa, but that would add more cost and weight and pollute more than the original concept of 1L turbo 3 cylinder flex fuel engine.

 

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40 miles would get me to work and back using no gas!

Thanks for clarifying, though I don't know how long Uncle Sam will offer the tax credit...would be simpler for Chevy to just lower the price on the next gen Volt!

Agreed...I'm in no hurry to trade in...I just love the technology and it's tempting to jump in. (By BEV, I'm assuming you mean Battery-Electric- Vehicle like the Leaf?) I would love to have a BEV and forgo gas altogether. The Leaf would get me to work and back with a little range left over. Keeping the Prius as a second car for long trips sounds good...all I need to do is convince my wife to trade in her Corolla which she loves but doesn't drive that much...I'm the one who racks up the miles!

 

46.5 today

Yes you got BEV right. And in a few years there will be more options beyond the Leaf, Tesla and iMev.

Good luck with your wife and the Corolla-> Prius conversion.

 

Presumably the idea in the Volt concept car was for the 3 cylinder 1.0L engine to be essentially the same GM Family 0 engine they have used for many years in the Opel/Vauxhaul Corsa in Europe but perhaps with a turbocharger added (like they did in the Cruze with the Family 0 1.4L):

[ame=http://en.wikipedia.org/wiki/GM_Family_0_engine]GM Family 0 engine - Wikipedia, the free encyclopedia[/ame]


Z10XEP 1.0 L Straight-3 (998 cc): 73.4 mm (2.89  in) bore, 78.6 mm (2.94 in) stroke, 10.5:1 compression, 60 hp (44 kW) @ 5600 rpm, 65 lbs.ft (88 Nm) @ 3800 rpm.

 

Short of it being cancelled the full amount is available for the first 200,000 PEVs from each manufacturer, so you have plenty of time, whatever you're planning to buy.

See Federal Tax Credit for Electric Vehicles Purchased in or after 2010
Scroll down to "Phase Out & Termination".

 

All this complication to "increase" efficiency to about the FE of my old 1989 Honda Civic station wagon! Prius: 50 mpg highway (my actual road trip mpg). Volt: 35 mpg in CS mode. I'd say they did a pretty lousy job of "increasing" efficiency with all that complicated rigamarole.

(The complicated mechanism is one of the biggest reasons I would not buy it. Compared to the elegantly simple mechanics of the Prius.)

I sure wish you were right. What are the numbers of hybrids, PHVs, and BEVs on the road today compared to gas-guzzlers? One in a thousand? One in ten thousand? I'm afraid we've only just introduced what is still a niche technology for tree-huggers and techie early adopters.

Note also, that if you compare to, say, the 1980's and 90's, most of this technology has gone to making cars bigger at the same mpg than to burning less gas per mile. With the exception of the Prius, and the minuscule numbers of BEVs and PHVs, cars are guzzling gas at greater rates than ever before.

Sadly, the days of guzzlers are not over. We're just seeing the first baby steps toward technologies with the potential to reduce gas use by a little bit.

Okay, you're joking, right? You want GM to say, "We don't think the taxpayer should subsidize us any more, so we're just going to lower the price of the Volt to where people could afford it, so that we'd have to build a car we never wanted to build in the first place, and make less money off it."

The whole point of the tax credit is that it's a give-away to the car companies and the rich people who have enough tax liability to be eligible for it.

 

I'm about to finish a road trip from SF-LA and back. I also did 190 miles worth of battery charging along the way but excluding that and just counting the gasoline miles, I'm getting 42-43 mpg mostly on the highway at 65 mph.

As for comparing your 1989 Civic to the Volt, I found the following on fueleconomy.gov.

Using the revised 2008 EPA estimate method:

1989 Honda Civic Station Wagon

City/Combined/Highway
26/29/32 (manual)
23/26/29 (automatic)

2012 Chevrolet Volt

City/Combined/Highway
35/37/40

 

I was not a fly on the wall, but assume they meant what they said and that was turbo charged. That 1L does not have the hp gm specified earlier. It does indeed take engineering effort to transform an engine well to turbo charging, and this takes money. Here is a take on the earliest look, and explanation for no di to save money. Ford spent the money to design what gm was talking about. There are not technical barriers, but ford is spreading the nre over a much larger number of engines.
Tech analysis of GM's new 1.4L four cylinder engine

Daniel, you obviously do not understand transmission design. In the most common mode EV the volts transmission is simpler than the prius Clutches in automatic transmissions have been popular for over 50 years. Your post seems to demonstrate ignorance of why the transmission is the way it is. Please at least read the motor trend comparison and why they thought the volts combination of universal gears and clutches is a better design. I do not think your civic station waggon can drive 35 miles as an ev, now can it. You are also completely wrong about which car is more efficient after you use up your battery.

This again is completely false. GM wanted to build the volt. Are you getting your talking points from fox news? Some have argued they should drop the price and lose money on each one like the original prius did to buy market share.

The tax credit is meant to encourage the development of plug-in technologies to help the country get off of oil. I do think it should be capped on very expensive cars like the karma and tesla roadster. If you are unhappy with your subsidy, I will be happy to give you a list of charities that you can donate the money to.

 

Tax incentive to start the development of plugin technologies? That doesn't sound good.

I believe tax incentive works well on technology that can reach the mainstream and stay profitable once the incentive is phased out. I don't believe in the incentives that is used to kick start the plugin that only reaches niche market.

To be more direct, I think Volt should have tax incentive starting from Gen2. Prius PHV should get the same amount as the Volt. They both have composite combined figure about 60 MPGe (only the result matters). Hybrids should also have a small incentive.

We shouldn't be offering incentives to kick start it. Incentives should be used to make them mainstream.

 

I understand you don't like these incentives. This discussion is probably more for FHOP than this forum. The prius phv also gets this incentive, so does not differ versus the volt. Certainly the SUV incentive that clinton passed to give "farmers" tax deductions worked extremely well. So well in fact that bush expanded it, and we have a great number of SUVs on the road. If the plug in incentives, which are similar to what MITI did to incubate the insight and prius, work half as well we will be using a lot less gas. The same problem of niche was put on the prius, but the japanese government had a long term perspective.

We saw that the hybrid deduction happened at a time where it was too late to really incubate sales. This represented give away to people that would have bought a hybrid anyway. If it had started in 2004 instead, maybe toyota would have ramped up production to satisfy the demand that happened. A small hybrid deduction will be much more expensive in absolute dollar terms than the plug intax credits. I would prefer that oil and ethanol subsidies be removed, which are more than 30 times what the plug in subsidy is currently. The person that put in a bill to kill the plug in subsidy, also voted to keep the oil subsidies, so we know where his true motivations lie. Will you at least decry oil and ethanol subsidies with equal strength as the plug-in one?

They need to be developed before high oil prices make them main stream. I don't think the government can afford to wait.

 

If batteries were free, or negligible in cost then absolutely it would make sense to make PHEVs and BEVs with as great a range as technologically feasible. But the reality is they are still a significant factor in the cost of a plugin vehicle. Given that, I believe most people look at PHEVs exactly backward. People naturally want a range that will cover all our own personal daily driving, with as little recharging as possible. Why would I want the hassle of plugging in if its not even going to cover my whole commute, and why recharge every day or even more than once a day if I can just have more battery? But on a national level, I would argue the greatest reduction in overall gasoline usage per $ invested will come from a large number of small batteries recharged as often as possible, rather than a lesser number of large batteries that are under utilized. The whole point of a PHEV vs. a BEV IMHO is that you can offset a given amount of gasoline with a given size battery, provided that you routinely deplete that battery and recharge it as often as possible. This is equally true if you drive a short distance all electric, or a long distance in blended mode.

I believe this graph from the 2009 survey is particularly relevant here, and answers drinnovation's concerns about the impact of the "0 distance" commuters on the average:



Now one assumption I am making is that potential PHEV customers will be equally distributed across this spectrum. Given the broad diversity of drive lengths and styles represented here on PriusChat for standard HEVs, which many might have argued only made sense for people that drive a lot, I believe this to be a fair assumption. Many people tend to buy these vehicles because they want to, not because they have a drive need that is ideally suited to the technology.

So taking the above data into account with my previous claims about the ideal application of PHEVs toward reducing national fuel consumption, one arrives at the following statistics. Assuming charge at work, the PiP 11 mile (official) range is either overkill or just reaching peak efficiency ($ invested vs. gallons offset) for ~55% of all commuters, and will achieve its maximum potential gasoline offset for the remaining 45%. The Volts 35 mile official range is either overkill or just reaching peak efficiency for 92% of commuters, and will achieve its maximum offset for the remaining 8%.

To get a quantitative idea of the relative potential impact of each, we can start with this non-cumulative version of the same data. I realize this introduces some quantization error due to its coarseness.


Integrating by multiplying the average value of each bin by the number of hits and renormalizing gives us a measure of percentage of total commute miles vs. average commute length. We can then use that data to get the total potential impact of each PHEV design range. To simplify the math I'm going to use 12.5 miles EV range for the PiP, and 37.5 miles for the Volt.

Av Com - % Commuters - % Com Miles - PiP saves - PiP %EV - Volt Saves - Volt % EV
2.5 mi ----- 25.5 % ------ 4.8 % ------ 4.8% ----- 100% ----- 4.8 % ----- 100%
7.5 mi ----- 24 % ------- 13.5 % ----- 13.5 % ---- 100% ---- 13.5 % ----- 100 %
12.5 mi ---- 16 % -------- 15 % ------ 15 % ------ 100% ---- 15 % ------- 100 %
17.5 mi ---- 11.5 % ------ 15 % ------ 10.7 % ---- 71.4 % -- 15 % ------- 100 %
22.5 mi ----- 7.5 % ------ 12.6 % ----- 7 % ------ 55.6 % -- 12.6 % ----- 100 %
27.5 mi ----- 5 % -------- 10.3 % ----- 4.7 % ---- 45.5 % -- 10.3 % ----- 100 %
32.5 mi ----- 3.5 % ------ 8.5 % ------ 3.3 % ---- 38.5 % --- 8.5 % ----- 100 %
37.5 mi ----- 2 % -------- 5.6 % ------ 1.9 % ---- 33.3 % --- 5.6 % ----- 100 %
42.5 mi ----- 1.5 % ------ 4.8 % ------ 1.4 % ---- 29.4 % --- 4.2 % ----- 88.2 %
47.5 mi ----- 0.75 % ----- 2.7 % ------ 0.7 % ---- 26.3 % --- 2.1 % ----- 78.9 %
52.5 mi ----- 1 % -------- 3.9 % ------ 0.9 % ---- 23.8 % --- 2.8 % ----- 71.4 %
57.5 mi ----- 0.25 % ----- 1.1 % ------ 0.2 % ---- 21.7 % --- 0.7 % ----- 65.2 %
62.5 mi ----- 0.5% ------- 2.3 % ------ 0.5 % ---- 20 % ----- 1.4 % ----- 60 %

Summing the PiP Saves and Volt Saves columns gives us the total potential commute gasoline miles saved for each vehicle, 64.5% for the PiP and 96.4% for the Volt.

Now in truth this is not the actual total potential savings for these vehicles, but rather the potential gasoline offset for a vehicle with average fleet fuel economy with the given EV range (12.5 mi and 37.5 mi) magically added. However this is consistent with the basis of the PHEV tax credit, only battery size matters, not efficiency. On that basis, the $2500 investment of federal tax dollars on each 12.5 mile PHEV yields an average gasoline consumption reduction of 64.5%, while the additional $5000 invested on a 37.5 mile PHEV only yields an additional 31.9%. From that standpoint, the first $2500 investment yields a far better return than the second and third $2500.

From that data I think its fairly clear that the federal tax incentive was written not based on getting the best bang for the buck, but rather to support GMs choice of range. By making the Volt cost nearly the same as the PiP, I would claim we are just incentivising people to buy more battery/range than they need or can necessarily use efficiently. I realize that there will be people who can use it all, and I'm sure they appreciate the extra cash. But when we're talking about spending Billions of dollars on what is essentially a public welfare project, one needs to look beyond individual benefit to statistical data to provide the most general welfare per $ invested.

One could also argue that the money spent on PHEV incentives could likely be just as effectively spent in increasing overall fuel economy as on PHEVs. A standard Prius HEV for example could likely decrease fuel consumption 50% across all travel distances. Of course to apply these incentives on a wide enough scale to matter, would also cost a lot of money bringing up the question of who pays for it? There is also an aspect that the purpose of the incentive is not just to reduce consumption, but to encourage technologies that will continue to further reduce consumption in the future. In this case higher volume battery production will drive down the cost and lead to greater range PHEVs and BEVs at a more economical cost in the future.

One solution would be to dis-incetivise low fuel efficiency vehicles on a proportional basis with a significantly increased fuel tax, and use the proceeds to fund public transit and advanced technology incentives such as PHEVs and BEVs as well as infrastructural incentives to companies and businesses to provide charging stations to make the charge after every trip assumption valid. But in general our current political climate is just to want the benefit without having to pay for it.

 

I don't know about EPA. I used to get around 35 mpg in my old Civic. That was just miles driven divided by gallons purchased

You are correct that I do not understand transmission design. But the Volt simply has more stuff that can go wrong. The Prius is a much simpler and more elegant design. And the Prius (both PiP and non-Pi) clearly get better mpg than the Volt after the grid charge is used up. The Volt's advantage is those 35 EV miles. But my Xebra had 40 EV miles (with an aftermarket pack) and my Tesla has 245 EV miles at 55 mph.

I do give money to charity. Some of it to charities that are not 501(c)3 because they don't believe in, in effect, taking money from the government.

I will also take whatever money the government, in its foolishness, decides to give me back from my (considerable) taxes. And I'll continue to advocate against what I think are ill-considered tax loopholes.

There's no contradiction there. I'd rather decide where my money goes. But I'll happily give up a tax break if it's also taken from everyone else.

 

Great post, miscrms!

 

First let me say this is a good first crack at some numbers.

I would say this is a bad assumptions. Initial adopters with very short commutes will go BEV, or not buy a plug in at all. Those with very long commutes will be tilted to a hv or something short range like the prius phv. THere are lots of theories, which is why my utility and US goverment are actualy collecting statistics.

You can play with figures, but most stats look at percentage of long trips. If there are no long trips and no short trips then phev or bev make a lot of sense. The split, number of times you can charge, are important to estimate savings. The average split for volt is about 2/3 electric, 1/3 gas. Savings can be calculated from there. The guesstimate is the prius phv will have a higher percentage of gasoline miles, but not enough have been sold to make accurate predictions. On a bev like the leaf, we need to add gas mileage for long trips that would have been made in a phev. Often these are in cars much less efficient than the prius or volt. I would estimate the savings in a prius phv as only one charge, 1/5 gallon of gas a day. But you need to credit the prius with better gas mileage versus those other cars than prius once that charge is gone.


Finally one thing that drives people to phevs is the electric drive experience. This should bias the surveys to cars with a greater electric proportion.

 

This sounds like a very bad assumption. Many people with short commutes still want a longer range for the weekend or for road trips. While two vehicles could solve this, there are those who want a single vehicle for all their automobile needs.

 

I also want to acknowledge that commuters are just one part of the puzzle. They just happen to be a convenient population to study as their travel patterns are fairly predictable and they represent a significant fraction of gasoline consumption. Looking at total vehicle mile driven for all purposes as represented in this graph is also valid.


This data seems to show significantly longer travel, which would change the analysis above. However the travel patterns are more complex, with more than a simple out and back commute. On average there are 4.2 trips per day rolled into this data, resulting in the below distribution of average trip length.



But again this data is harder to make assumptions about, as there is a lot more deviation spread about the average, as well as variables such as time between trips, availability of charging at non-work locations, etc that would have to be considered. In general I believe the same basic conclusions would apply, but its harder to prove without making a lot of assumptions.

 

I would have to agree. In studying statistical data like this its easy to make simplifying assumptions about what people "should" do, or what vehicle they "should" buy. Again I think the diversity of the population here on Priuschat is a good example of how people don't necessarily follow that logic, and in fact represent a pretty broad range of the spectrum.

 

Hey there definitely can be people in that category. The nice thing about assumptions is they can be tested with data. I did say very short commutes, by which I mean daily driving is 8 miles or less. In a few years we should see if these people with very short commutes buy phevs. I expect this number to be low. If these folks do take a lot of long trips, that trip mileage will be a significant portion of total mileage, and daily mileage is not as much of a benchmark on percent electrical. Looking at the daily mileage graph, the percent that can do their daily drive on electricity in the prius phv is 20% for the volt is over 60%. Let's say a phv driver can charge every day, and gets 11 electric miles (that's slightly higher than epa). That's 4000 miles a year. If they drive 8000, miles per year half will be electric and they will only burn 80 gallons of gas (warning I'm assuming 50mpg on these miles). Driving 12000 miles a year which is more typical for Americans will burn 160 gallons, still very low. Let's say the volt driver also goes 12K miles, and long trips make 4000 of these gas, then he will burn 108 gallons of gas. This is similar enough to the prius driver to make other factors than mpg important.

I definitely agree with the single vehicle story though.

 

Note though that as mentioned above the daily drive numbers represent multiple trips per day of varying lengths. Hence the importance of the the trip length distribution plot. If you make the assumption that PHEVs can only charged once a day, then it does make a longer range look more favorable in the wider non-commuter pool. I would argue however that rather than investing more money in bigger batteries, that same money would be better spent providing the charging infrastructure to use smaller batteries as efficiently as possible by recharging them more often.

 

Utilities are closely looking at this question. If cars are charged primarily at night there is a surplus of generation If they are charged all through the day, then many places will need to add peaking generating equipment. The question is open. I would assume that most, especially where I live with smart grid, will primarily charge only once per day. This is especially true where I live, where more night charging means more wind. We should definitely test this assumption though.

If you look at the phv sizing, it is appropriate for the japanese market, but can save gas in the us market.

The current government program incentives small battery phev more than big battery. If you divide the electric mile premium it is higher in the current plan. The prius phv has a credit of $570/kwh and it would be higher if it was 4 or 5 instead of 4.4kwh. The volt has a credit of $470/kwh , the leaf $310/kwh. In my area there are also municipal utility, state, federal, and private corporate money that is being put into the infrastructure. So I would argue we can walk and chew gum at the same time, and incentives are going to your priorities.