2008 J.D. Power Initial Quality Study: Porsche, Honda, Chevroletamong big winners

http://www.jdpower.com/corporate/new...spx?ID=2008063

"Elle" > wrote in message
...
> "C. E. White" > wrote
>> JD Powers also has a survey that address longer term reliability (3
>> years). I suspect this is about as long as is meaningful. After three
>> years I suspect owner treatment of the vehicles becomes a significant
>> factor in reliability.
>
> All sort of holes may be poked into conclusions drawn from any survey.
>
>> I've never had much respect for the CR survey results. I've answered them
>> for years, but think doing so is largely a waste of times. The survey is
>> far from random
>
> The CR survey is as random as Power's ridiculously useless survey.

It is not random at all. They only survey CR readers, and then only readers
who wish to respond. I've always felt this biases the results of the CR
survey to match the editorial opinions of the CR staff. In recent years CR
has done a better job of massaging the results, but I still think they are
suspect.

And why do you think the JD Power survey is useless? It is a true random
survey. They collect much more information than CR does.

>> and they collect too little information to make the broad pronouncements
>> given in the magazines.
>
> Based on the numbers surveyed, combined with the number of years covered,
> the results are most likely statistically significant.

And you know this because? Does it ever bother you that the results for
different year model of a particular model that should be essentially the
same parts get vastly different reliability ratings in some categories from
year to year?

>> The little circles they display in the magazine are also misleading. They
>> over emphasize the difference between vehicles.
>
> CR explains precisely what the difference between circle coloring means.

OK, what exactly do they mean.....I mean besides Excellent, Very Good, Good,
Fair and Poor. For '07 cars, the average problem rate for the worst category
(Body Integrity) was only 3%. What do you suppose the accuracy of the CR
Survey is? I'll bet it is a lot worse than 3%.

So, CR surveys a select group, that is more likely than the general
population to agree with there opinions, they don't provide data on the
number of vehicles of a particular type surveyed, or the even what average
means, yet you think they are highly accurate.....

Ed

"C. E. White" > wrote in message
m...
>
> "Elle" > wrote in message
> ...
>> "C. E. White" > wrote
>>> JD Powers also has a survey that address longer term reliability (3
>>> years). I suspect this is about as long as is meaningful. After three
>>> years I suspect owner treatment of the vehicles becomes a significant
>>> factor in reliability.
>>
>> All sort of holes may be poked into conclusions drawn from any survey.
>>
>>> I've never had much respect for the CR survey results. I've answered
>>> them for years, but think doing so is largely a waste of times. The
>>> survey is far from random
>>
>> The CR survey is as random as Power's ridiculously useless survey.
>
> It is not random at all. They only survey CR readers, and then only
> readers who wish to respond. I've always felt this biases the results of
> the CR survey to match the editorial opinions of the CR staff. In recent
> years CR has done a better job of massaging the results, but I still think
> they are suspect.
>
> And why do you think the JD Power survey is useless? It is a true random
> survey. They collect much more information than CR does.
>

What benefit is it of CR to massage the responses you and I give to the
survey? Their business is to test stuff and provide the results. You may not
test the same way they do, or come away with the same conclusions, but that
does not change their mission in life.

When you report your experience on your '05 Camry, or whatever, they only
compile that experience with all others reporting on the same car. They
don't care what the response is, they are only interested in the relative
responses so they can derive an average response, then denote it with a
symbol that essentially gives a rating on a scale of 1 to 5.

If they get 100 responses, the sample size is not so large, but if they get
100,000 responses then the sample size is very large and by statistical
standards, very reliable.




>>> and they collect too little information to make the broad pronouncements
>>> given in the magazines.
>>
>> Based on the numbers surveyed, combined with the number of years covered,
>> the results are most likely statistically significant.
>
> And you know this because? Does it ever bother you that the results for
> different year model of a particular model that should be essentially the
> same parts get vastly different reliability ratings in some categories
> from year to year?
>

No, it does not bother me at all.

You are asking if it concerns me that a Ford Crown Vic a Mercury Marquis and
a Lincoln Towne Car can score differently. No. I suspect the buyers might
have different expectations of quality between a Ford a Mercury and a
Lincoln, and this can feed into the satisfaction each customer has in his
car. It is also possible that the different cars are built to different
standards, and the more costly unit is actually built better. I don't know
the specifics of the response, but if I was in the market for a used car, I
would at least look at the models I was interested in to see what others
were, or were not, happy with, and I would also look at the same car with
different name plates. Mazda CX7 owners might like their car, but Ford Edge
owners might not be so happy. That might be useful information in a Used Car
search.





>>> The little circles they display in the magazine are also misleading.
>>> They over emphasize the difference between vehicles.
>>
>> CR explains precisely what the difference between circle coloring means.
>
> OK, what exactly do they mean.....I mean besides Excellent, Very Good,
> Good, Fair and Poor. For '07 cars, the average problem rate for the worst
> category (Body Integrity) was only 3%. What do you suppose the accuracy of
> the CR Survey is? I'll bet it is a lot worse than 3%.
>
> So, CR surveys a select group, that is more likely than the general
> population to agree with there opinions, they don't provide data on the
> number of vehicles of a particular type surveyed, or the even what average
> means, yet you think they are highly accurate.....

Actually, they don't select a group at all. They mail out a questionaire to
ALL SUBSCRIBERS, who then complete them and send them in to be tallied.

You are correct in that they (CR) does not provide the sample size, so you
do not know if you are looking at 100 responses or 100,000, or 10. Having
said that, I recall that they do have a minimum sample size, and if they
don't get enough responses, then they put N/A on the table. One or two
people that like or dislike a feature is not a valid response. I don't know
how many responses it takes to get a statistically valid response, but
surely a sample size that is too small does not give valid data.

"C. E. White" > wrote
> "Elle" > wrote
>> "C. E. White" > wrote
>>> JD Powers also has a survey that address longer term
>>> reliability (3 years). I suspect this is about as long
>>> as is meaningful. After three years I suspect owner
>>> treatment of the vehicles becomes a significant factor
>>> in reliability.
>>
>> All sort of holes may be poked into conclusions drawn
>> from any survey.
>>
>>> I've never had much respect for the CR survey results.
>>> I've answered them for years, but think doing so is
>>> largely a waste of times. The survey is far from random
>>
>> The CR survey is as random as Power's ridiculously
>> useless survey.
>
> It is not random at all. They only survey CR readers, and
> then only readers who wish to respond.

J.D. Power also only surveys those who wish to respond. I
can't see how the self-selection is any worse.

> I've always felt this biases the results of the CR survey
> to match the editorial opinions of the CR staff. In recent
> years CR has done a better job of massaging the results,

What motive would CR editors have to massage what CR readers
submit?

"Editorial" is way too strong a descriptor for the quality
reviews of the cars (not the matrices of reader experiences)
that CR testers perform. The tests the CR staff does has
results all over the map. Sometimes Ford gets a good rating,
sometimes VW, and so on.

The reader surveys OTOH consistently rate Toyota and Honda
as the best makes of cars.

but I still think they are
> suspect.
>
> And why do you think the JD Power survey is useless? It is
> a true random survey. They collect much more information
> than CR does.
>
>>> and they collect too little information to make the
>>> broad pronouncements given in the magazines.
>>
>> Based on the numbers surveyed, combined with the number
>> of years covered, the results are most likely
>> statistically significant.
>
> And you know this because? Does it ever bother you that
> the results for different year model of a particular model
> that should be essentially the same parts get vastly
> different reliability ratings in some categories from year
> to year?

Not for Hondas and Toyotas, with the exception of an
occasionally new design, like the Toyota Tundra c. 2004.

>>> The little circles they display in the magazine are also
>>> misleading. They over emphasize the difference between
>>> vehicles.
>>
>> CR explains precisely what the difference between circle
>> coloring means.
>
> OK, what exactly do they mean.....I mean besides
> Excellent, Very Good, Good, Fair and Poor. For '07 cars,
> the average problem rate for the worst category (Body
> Integrity) was only 3%.

Sounds like you have been reading the articles. I do not
have the April issue handy, but what the circles mean is
described prominently.

> What do you suppose the accuracy of the CR Survey is? I'll
> bet it is a lot worse than 3%.

See my post to Jeff. The "accuracy" of the CR surveys should
be better than that of J.D. Power's dependability survey,
because the sample size per model appears to be larger.
(Neither JD Power nor CR give the exact number of owners per
model surveyed.) You can still argue CR reader bias, I
suppose. Though, come on, what does that mean here? CR
readers are no more likely to ignore car problem than anyone
else, are they? Or do we want to sample car owners who get a
breakdown and ignore the car for the next two years? Or
those who do not like to maintain their car? You do realize
those who do not follow the maintenance schedule throw every
damn thing off when it comes to surveys, right?

It's mostly going to be differences between two models that
are statistically significant, meaning it's reasonable to
conclude another car randomly chosen from a population of
this model will perform X better than another model with a
worse rating.

> So, CR surveys a select group, that is more likely than
> the general population to agree with there opinions, they
> don't provide data on the number of vehicles of a
> particular type surveyed, or the even what average means,

Nor does J.D. Power state exactly how much input it had for
each model.

Plus, for dependability J.D. Power looks only at three-year
old cars, by all indications from a sample arguably as
self-selected as CR's.

"Elle" > wrote in message
...
> "C. E. White" > wrote
>> "Elle" > wrote
>>> "C. E. White" > wrote
>>>> JD Powers also has a survey that address longer term reliability (3
>>>> years). I suspect this is about as long as is meaningful. After three
>>>> years I suspect owner treatment of the vehicles becomes a significant
>>>> factor in reliability.
>>>
>>> All sort of holes may be poked into conclusions drawn from any survey.
>>>
>>>> I've never had much respect for the CR survey results. I've answered
>>>> them for years, but think doing so is largely a waste of times. The
>>>> survey is far from random
>>>
>>> The CR survey is as random as Power's ridiculously useless survey.
>>
>> It is not random at all. They only survey CR readers, and then only
>> readers who wish to respond.
>
> J.D. Power also only surveys those who wish to respond. I can't see how
> the self-selection is any worse.
>
>> I've always felt this biases the results of the CR survey to match the
>> editorial opinions of the CR staff. In recent years CR has done a better
>> job of massaging the results,
>
> What motive would CR editors have to massage what CR readers submit?
>
> "Editorial" is way too strong a descriptor for the quality reviews of the
> cars (not the matrices of reader experiences) that CR testers perform. The
> tests the CR staff does has results all over the map. Sometimes Ford gets
> a good rating, sometimes VW, and so on.
>
> The reader surveys OTOH consistently rate Toyota and Honda as the best
> makes of cars.
>
> but I still think they are
>> suspect.
>>
>> And why do you think the JD Power survey is useless? It is a true random
>> survey. They collect much more information than CR does.
>>
>>>> and they collect too little information to make the broad
>>>> pronouncements given in the magazines.
>>>
>>> Based on the numbers surveyed, combined with the number of years
>>> covered, the results are most likely statistically significant.
>>
>> And you know this because? Does it ever bother you that the results for
>> different year model of a particular model that should be essentially the
>> same parts get vastly different reliability ratings in some categories
>> from year to year?
>
> Not for Hondas and Toyotas, with the exception of an occasionally new
> design, like the Toyota Tundra c. 2004.

Not true. For instance, for 2002-2006 Camrys, the quality of the suspension
varied from very good to excellent from, almost at random. The fuel system
went from very good to excellent to good without any significant changes to
the design. So did the ratings of body hardware. For some reason, '03 have
worse cooling systems that an other year (but according to the parts
catalog, the parts are the same....). I suppose you are going to point out
that chages from very good to excellent are trival, but then that is my
point. The differences are trivial, probably well within the accuracy of the
survey. CR takes poorly collected data (not random, poor questions),
massages it, and presents it as little circles that really don't mean
anything. At least JD Powers gives you a number (number of problems reported
per 100 vehicels) and at least they start out with a random sample. I
suppose you should stay away from any vehicle with solid black circles, but
how many fall into that category? Do you really think there is much
difference between vehicles that rate good or better?

>>>> The little circles they display in the magazine are also misleading.
>>>> They over emphasize the difference between vehicles.
>>>
>>> CR explains precisely what the difference between circle coloring means.
>>
>> OK, what exactly do they mean.....I mean besides Excellent, Very Good,
>> Good, Fair and Poor. For '07 cars, the average problem rate for the worst
>> category (Body Integrity) was only 3%.
>
> Sounds like you have been reading the articles. I do not have the April
> issue handy, but what the circles mean is described prominently.
>
>> What do you suppose the accuracy of the CR Survey is? I'll bet it is a
>> lot worse than 3%.
>
> See my post to Jeff. The "accuracy" of the CR surveys should be better
> than that of J.D. Power's dependability survey, because the sample size
> per model appears to be larger.

A large but biased sample is not going to give better results.

> (Neither JD Power nor CR give the exact number of owners per model
> surveyed.) You can still argue CR reader bias, I suppose. Though, come on,
> what does that mean here? CR readers are no more likely to ignore car
> problem than anyone else, are they? Or do we want to sample car owners who
> get a breakdown and ignore the car for the next two years? Or those who do
> not like to maintain their car? You do realize those who do not follow the
> maintenance schedule throw every damn thing off when it comes to surveys,
> right?

Have you completes a CR survey? There is a fair amount of room for
iterpertation of the questions.

> It's mostly going to be differences between two models that are
> statistically significant, meaning it's reasonable to conclude another car
> randomly chosen from a population of this model will perform X better than
> another model with a worse rating.

So how much statictical difference is there between an Accord and a Camry?
CR predicts a new Camry will have worse than average reliability. A new
Accord will have better than average reliability. What does that mean? If I
buy a Camry instead of an Accord am I likely to have one more problem, or
two, or ten, or twenty? If you can't tell me from the CR predicitions, what
good are they? At least if you look at the JD Power numbers you can get an
idea that the spread between vehicles is very small, much smaller than CR's
reporting methods suggests. In the latest initial quality survey, the
difference between the best vehicle manufacturer (Porsche) and the worst
(Mini) was 0.8 problems per vehicle. In the 2007 Vehciel Dependability
Study, the difference between the most dependable manufacturers (Buick and
Lexus) and the least dependable (Land Rover) was 2.5 problems. This shoudl
tell you that the differences are down in the noise range, and the little
circles that CR uses are trying to divide up very trivial differences into 5
categories. If you start with data that is poorly collected and then try to
use it to indicate trivial distinctions, you are not being fair. At least
with JD Powers, you can see for yourself that most cars are pretty good. I
have no problem with people claiming Land Rovers are less reliable that
Lexi, but I doubt the difference is near as significant as Lexus owners
would like to think.

>> So, CR surveys a select group, that is more likely than the general
>> population to agree with there opinions, they don't provide data on the
>> number of vehicles of a particular type surveyed, or the even what
>> average means,
>
> Nor does J.D. Power state exactly how much input it had for each model.
>
> Plus, for dependability J.D. Power looks only at three-year old cars, by
> all indications from a sample arguably as self-selected as CR's.

JD Powers starts out with a random sample. CR starts out with their
subscribers.

Ed

"C. E. White" > wrote
> Not true. For instance, for 2002-2006 Camrys, the quality
> of the suspension varied from very good to excellent from,
> almost at random.

Oh my god, good to excellent.

I think the consistency of the almost all red (meaning
good-to-excellent) reliability matrices for Hondas and
Toyotas speak for themselves. Black circles are rare for
them. I am not posting for your benefit. You're dug into a
political belief here. I am posting for others'. Go to CR
and go to J.D. Power. Just do not go to J.D. Power by
itself.

> A large but biased sample is not going to give better
> results.

You have proved no more bias in CR than in J.D. Power,
either in its questions or in the group it samples.

CR's million owners surveyed per year over ten years trumps
J.D. Power's hogwash 3-year-old vehicle survey of some
57,000 owners.

"C. E. White" > wrote in message
> I've never had much respect for the CR survey results. I've answered them
> for years, but think doing so is largely a waste of times. The survey is
> far from random and they collect too little information to make the broad
> pronouncements given in the magazines. The little circles they display in
> the magazine are also misleading. They over emphasize the difference
> between vehicles.

Many ears ago I gave up or CR as a reliable source of information. My
personal experience was far different than theirs in many cases and what
they perceived as a problem, I'd perceive as a feature.

On Mon, 9 Jun 2008 09:04:29 -0700, "Elle"
> wrote:

>"Jeff Strickland" > wrote
>> Any survey is dependent upon the sheer number of
>> participants/respondants, and the more there are the
>> greater the accuracy of the data. With any survey, if one
>> throws out the top and bottom extremes of the response
>> curve, the result should be relatively level and a
>> reasonably accurate indicator of the overall feeling of
>> the sample group.
>
>? The extremes cancel each other out and should not affect
>the average in any significant way, assuming the sample size
>is large enough.
>
>> I don't think that JD Powers and Consumer Reports will
>> attract significantly different samples.
>
>Sample size per year-model seems about the same for the IQS
>and CR surveys. Power is not as forthcoming, IMO, about
>sample size per vehicle.
>Links at http://www.jdpower.com/autos/car-ratings/ ,
>says Power used input from 97,000 car owners for the IQS.
>The input covers I guess over 100 different models. (I am
>too lazy to count them all up.) So there's input of maybe
>around 1000 owners for each model.
>
>J.D. Power's 2007 dependability ratings (for three year old
>cars, asking about problems in the last 12 months) use input
>from a paltry 53,000 car owners.
>
>CR uses input from 1 million owners, covering 1100
>model-years for the past decade. So CR is using the input of
>about 1000 owners per model-year. So I'd guesstimate that
>CR's input is of higher statistical significance for any
>given model-year. Take a few years running where the model
>design is known not to have changed a lot, and CR is of much
>higher statistical significance.

Which hints at a big CR strength; presentation of the data. With CR
you can quickly see the entire history of each system in each model.
You can quickly spot the year they fixed the transmission or whether
manufacturer X has problems with the first model year of a new design.

On Mon, 9 Jun 2008 14:51:37 -0400, "C. E. White"
> wrote:

>
>"Elle" > wrote in message
...
>> "C. E. White" > wrote
>>> JD Powers also has a survey that address longer term reliability (3
>>> years). I suspect this is about as long as is meaningful. After three
>>> years I suspect owner treatment of the vehicles becomes a significant
>>> factor in reliability.
>>
>> All sort of holes may be poked into conclusions drawn from any survey.
>>
>>> I've never had much respect for the CR survey results. I've answered them
>>> for years, but think doing so is largely a waste of times. The survey is
>>> far from random
>>
>> The CR survey is as random as Power's ridiculously useless survey.
>
>It is not random at all. They only survey CR readers, and then only readers
>who wish to respond. I've always felt this biases the results of the CR
>survey to match the editorial opinions of the CR staff. In recent years CR
>has done a better job of massaging the results, but I still think they are
>suspect.
>
>And why do you think the JD Power survey is useless? It is a true random
>survey. They collect much more information than CR does.
>
>>> and they collect too little information to make the broad pronouncements
>>> given in the magazines.
>>
>> Based on the numbers surveyed, combined with the number of years covered,
>> the results are most likely statistically significant.
>
>And you know this because? Does it ever bother you that the results for
>different year model of a particular model that should be essentially the
>same parts get vastly different reliability ratings in some categories from
>year to year?

This is like an Internet mythology. Without your citing specific
instances where this is the case, it is pretty hard to respond. As
far as I can see, related vehicles usually have very similar
reliability records.


>
>>> The little circles they display in the magazine are also misleading. They
>>> over emphasize the difference between vehicles.
>>
>> CR explains precisely what the difference between circle coloring means.
>
>OK, what exactly do they mean.....I mean besides Excellent, Very Good, Good,
>Fair and Poor. For '07 cars, the average problem rate for the worst category
>(Body Integrity) was only 3%. What do you suppose the accuracy of the CR
>Survey is? I'll bet it is a lot worse than 3%.

The average model year had about 7000 responses. A 1% failure rate
represents 70 respondents (typically) who reported a problem. My
guestimate is this is a lot better than a 3% margin of error.

>So, CR surveys a select group, that is more likely than the general
>population to agree with there opinions, they don't provide data on the
>number of vehicles of a particular type surveyed, or the even what average
>means, yet you think they are highly accurate.....

The opinions are irrelevant. The question is, did you have to repair
the transmission last year, yes or no? If the survey is inaccurate,
it has produced some uncanny results. For example: Honda, of course,
has a stellar repair record - traditionally neck and neck with Toyota
for best in the world. Yet one year, CR reported that one feature on
one Honda model had the worst repair record in the survey. That would
seem to indicate that the survey respondents weren't influenced by
preconceived opinions.

On Mon, 9 Jun 2008 16:53:59 -0400, "C. E. White"
> wrote:

>
>"Elle" > wrote in message
...
>> "C. E. White" > wrote
>>> "Elle" > wrote
>>>> "C. E. White" > wrote
>>>>> JD Powers also has a survey that address longer term reliability (3
>>>>> years). I suspect this is about as long as is meaningful. After three
>>>>> years I suspect owner treatment of the vehicles becomes a significant
>>>>> factor in reliability.
>>>>
>>>> All sort of holes may be poked into conclusions drawn from any survey.
>>>>
>>>>> I've never had much respect for the CR survey results. I've answered
>>>>> them for years, but think doing so is largely a waste of times. The
>>>>> survey is far from random
>>>>
>>>> The CR survey is as random as Power's ridiculously useless survey.
>>>
>>> It is not random at all. They only survey CR readers, and then only
>>> readers who wish to respond.
>>
>> J.D. Power also only surveys those who wish to respond. I can't see how
>> the self-selection is any worse.
>>
>>> I've always felt this biases the results of the CR survey to match the
>>> editorial opinions of the CR staff. In recent years CR has done a better
>>> job of massaging the results,
>>
>> What motive would CR editors have to massage what CR readers submit?
>>
>> "Editorial" is way too strong a descriptor for the quality reviews of the
>> cars (not the matrices of reader experiences) that CR testers perform. The
>> tests the CR staff does has results all over the map. Sometimes Ford gets
>> a good rating, sometimes VW, and so on.
>>
>> The reader surveys OTOH consistently rate Toyota and Honda as the best
>> makes of cars.
>>
>> but I still think they are
>>> suspect.
>>>
>>> And why do you think the JD Power survey is useless? It is a true random
>>> survey. They collect much more information than CR does.
>>>
>>>>> and they collect too little information to make the broad
>>>>> pronouncements given in the magazines.
>>>>
>>>> Based on the numbers surveyed, combined with the number of years
>>>> covered, the results are most likely statistically significant.
>>>
>>> And you know this because? Does it ever bother you that the results for
>>> different year model of a particular model that should be essentially the
>>> same parts get vastly different reliability ratings in some categories
>>> from year to year?
>>
>> Not for Hondas and Toyotas, with the exception of an occasionally new
>> design, like the Toyota Tundra c. 2004.
>
>Not true. For instance, for 2002-2006 Camrys, the quality of the suspension
>varied from very good to excellent from, almost at random.

And on Impala the range is from poor to very poor (mostly the latter.)
Doesn't sound like there is any trouble distinguishing which of these
vehicles has a more reliable suspension system.

> The fuel system
>went from very good to excellent to good without any significant changes to
>the design.

And Impala ranges from good to poor. I think you are having trouble
seeing the forest because all the trees are in the way. Step back and
look at the big picture.




So did the ratings of body hardware. For some reason, '03 have
>worse cooling systems that an other year (but according to the parts
>catalog, the parts are the same....).

Have you ever heard of a bad batch of parts? Changing suppliers? To
be honest with you, I am looking at the 2008 CR survey right now and
2003 Camrys are the same as 2002 and 2004.

> I suppose you are going to point out
>that chages from very good to excellent are trival, but then that is my
>point. The differences are trivial, probably well within the accuracy of the
>survey. CR takes poorly collected data (not random, poor questions),
>massages it, and presents it as little circles that really don't mean
>anything. At least JD Powers gives you a number (number of problems reported
>per 100 vehicels)

With no breakdown of what those problems are.

> and at least they start out with a random sample. I
>suppose you should stay away from any vehicle with solid black circles, but
>how many fall into that category?

None if you are dealing with Toyota or Honda. If you look at GM,
Chrysler, Mercedes, Kia, Nissan, Ford and VW, there is a wide
selection of models to choose from.