Plug-In Prius misrepresentation

You misread your link. The ICE/range extender is this spec:

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Secondary power: 84 hp @ 4,800 rpm; 93 lb ft

Read more: http://www.automobilemag.com/am/2013/chevrolet/volt/specifications.html#ixzz29FA55olM​

 

Sorry about that. So the correct reading is that the ICE on the Plug-In is 98 hp and for the Volt it is 84 hp?

I guess I fell victim to the Prius Plug-In mindset that that EV is the secondary power source, whereas on the Volt, the ICE is considered the secondary power source.

Thanks for the correction.

 

Another "misrepresentation" (mostly in the comments)

2012 Toyota Prius Plug-In Hybrid: Is It An Electric Car, Or Not?


The article is not flattering but mostly factual with clearly personal opinions from the writer. There are commenters that are tossing out the 6mile stuff (I corrected them and various other incorrect or misleading statements in the among the commenters)

 

Yup, I jumped in too.

Dennis

 

yes though mostly you seem to want to attack the volt, not correct misinformation about the PHV.
I can see your misrepresenttions and attacks on the Volt are not limited to PC Chat. neither is my defense.

 

Which one are you referring to? The charging time?

 

On the topic of emission, the chart was made from the data in CARB emission certificate. The Volt (CA) shown is the special cleaner version available in California that qualifies for the HOV lane. It is not available in all states.

 

EPA also rate the plugin vehicle emission by combining the tailpipe and upstream (fuel production) emission together. Using average emission in the entire United States, this is how it came out after I sampled one zip code from each state. For more info, see this thread which includes the source of data, etc.

 

Not trying to be negative here.. but I've not seen the real-world data (though I don't doubt) showing the cold start is not the most emission intensive part of the PHV, or that the RPMs stay low even when the ICE starts because of power demands. Is there a thread with an OBDII or scan gauge reading of RPMs when hard accelerations cause the ICE to start, or on measurements of emissions from starting under hard acceleration? Only data I've seen on emissions is from standard testing which is averaged over full cycles.

 

I think the claim that "most trips" are short is generally backed up by the National Household Travel Survey. The last data was from 2009, and will be refreshed in 2015. Looking at the distribution trip lengths of all types, it does seem one can claim that most trips are "short." From the data below about 80% of all trips made in the US are under 12 miles.




The average length and frequency of trips by type can be read from the NHTS data here:
SAS Output
SAS Output
Trips to work account for 16.2% of the trips made, so presumably round trip commutes account for about 32% of all trips.

The trip data is really only meaningful if one assumes you could recharge after every trip, which I think we can safely say is not typically feasible given the current infrastructural support for plug-in vehicles. More meaningful then is probably looking at the average vehicle miles per day from the same data.


Assuming a recharge of once per day, the PiPs 11 mi range would completely cover about 20% of the populations averaged daily needs mostly electric. At twice per day, its about 45%. The Volts 40 mi range should cover almost 70% of the populations average daily needs. Those ranges about double if the goal is 50% fuel reduction rather than trying to go all electric. The Volt may have broader appeal, while the PiP focuses on the conversion of the "low hanging fruit" of those whose needs can most easily be met with a PHEV. Without the government subsidy of the Volt, the penalty for this broader approach in terms of cost would be more severe. As it is, the subsidy is helping get more batteries on the road, which I can't really argue with.

As John mentioned, this is consistent with the average mpg by the average driver being higher for the Volt than the PiP. The trick is that governments and auto-makers are mostly concerned with averages and populations, as money alluded to above, the averages are largely irrelevant to the individual. As individuals you have to chose what makes the most sense for you. For some the Volt will be a better fit, for some the PiP will.

NHTS data:
NHTS Online Analysis Tools
Graphs and EV interpretation from:
Can EVs handle the distances we drive? • A Study

Rob

 

That's a good question. Toyota does seem to have done an excellent job of cleaning up their already low cold start emissions in the Prius PHV under low demand conditions.

I wonder what the typical ratio is for mild cold starts due to running low on battery SOC or modest accelerations that slightly exceeds EV capability vs. harder acceleration cold starts. Obviously it is very dependent on driving patterns and driving style. Drivers who are aware of the issue can easily avoid hard cold starts in non-emergency conditions.

 

The Volt does roughly the same thing. By "low SOC" I meant the lower SOC target which causes the gas engine start. On the Volt it is around 20-22% battery charge but several percent more can be drawn down if you were to accelerate hard. I think the Prius PHV lower SOC target has been reported around here but I don't remember exactly what it is now. I'm reasonably sure it's also between 20-30%.

 

Spin it any way you want to. Hauling around more weight creates drag. Of course, if you're full of gas to begin with, then it's really not a problem.

By the way, as far as meaningful data goes, the curb weight of the Volt is 3781 lb. The curb weight of the Prius PHEV is 3165lb.

 

Not sure what you consider spin.. you said the Volt had a larger engine.. it does not.

Agreed weight creates drag and the volt weights more. What's your point?
The battery, without coolant is 465lb,. The motors are are also bigger/heavier. These are needed to make it perform like true EV with range extender. For me, and many others, the added weight that's worth the higher drag. For most drivers that bigger battery allows much lower overall gas usage, it seems a valuable choice for them. Voltstats has the Median driver at 179MPG, average at 129MPG.. where is the median/average Prius PHV driver?

Having a range extender, with 40mpg highway, is not dead weight. If I had a Leaf, I would have used 25 gallos MORE gas than the Volt, because my long trips would need to use the other car (a CUV).

 

FWIW, assuming all else is equal, the weight and CdA difference should make the Volt consume about 16.6% more fuel/power at 50mph, and about 18% more at 30mph. That's about 50mpg vs. 42.9 mpg at 50mph. The additional mpg difference would likely be due to the engine and/or drivetrain efficiency differences.

Theoretically the PiP is more efficient at using both fuels. Unfortunately, due to the ratio of EV to HV most people will experience in their typical driving, the Volt will likely use less fuel overall due to the efficiency advantage inherent to electric drive. The exceptions should be short trips (<10-12 mi if you can avoid lighting the ICE, and maybe even slightly longer or with minimal ICE use), and very long trips (> 100-120 mi is I think the estimated crossover point). If these sorts of trips make up the bulk of your driving, the PiP may be more efficient overall. Otherwise the Volt probably will be.

The Volt ought to cost significantly more than the PiP, which should be the main penalty for its big battery. But given the tax incentive structure, for many people its probably worth considering at least on an overall fuel usage basis. There are reasons I wouldn't buy one, mostly not a great family car and not a big GM fan, but have to admit the government solved my one big complaint about the Volt design (cost penalty of the big battery). You could argue whether that was an unfair advantage, but in as far as it gets more batteries on the road sooner I can't really complain much.

Rob

 

Rob, you bring up some good points but there's one you missed because you haven't (I assume) driven a Volt and that point is full electrical propulsion. Once you drive a car with it and become quickly accustom to it, issues like which is more efficient at 50mph or at X distance become, well not meaningless, but quickly disappear from the radar. The smooth effortless torque delivered in silence (no gear whine) at any speed pays off in dividends that just can't be measured by any metric except maybe grins.

YMMV

 

Two weeks later I took my Toyota Plug-in back to the shop because I dropped down to 9.5 usable mileage. I am very disappointed with my Toyota Plug-in because 2 months ago and have 1400 miles on car. When I first charged it up with the 110 volt charger supplied with the car, I got 13.4 miles to use up before the car went off battery. Then on recharges, every two or three times when the battery recharged the usable mileage dropped by a 1/10 a point. I now have only 9.5 miles to use before I go off battery. I wonder how low it is going to go? I took it into Gladstone Toyota and had the service department look at it. They said after they recharged it and found it to be only 9.5 and that there is nothing they can do unless the red warning light comes on saying that the battery is defective. I asked them how low the battery would go and still considered normal, and they said they did not know. So I guess I will keep loosing free electric miles. Don't buy this car until they solve their battery problems