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Discussion Starter #1
In late 2005 I started conducting my own reliability research. I'm reporting absolute stats like "times in the shop" that will make the differences between cars much clearer. Relative ratings obscure too much--how large is the difference between "better than average" and "worse than average"? I’ll also be updating results four times a year, so there will be information on new models sooner.

I'm about halfway to the minimum to start collecting data for the 2004 and 2005 Pacifica, and would like to be able to provide information on all model years. Especially the 2007, with its new powertrain.

To encourage participation, panel members will receive full access to the results free of charge.

Details: Vehicle reliability research

Comments, questions, and suggestions welcome.
 

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Started collecting data on the 2005, but will probably need more participants before I can post results.

Other years getting closer.

I ran my 2005 AWD Touring up to 89500 miles ansd had no issues at all, except for mpg seemed to stay at 18-19 on the highway. Great car for me and I had it since March of 2005. I just traded it in on a 2007 base AWD 4.0L, and I plan a few upgrades:

- Auto Temp control (ATC) (I am hoping this is just a MTC to ATC unit switch, but I am not sure yet.) :unsure:
- Autoheadlight and Fog light multifunction switch (if the Autoheadlights key off of the AutoDimming mirror, then I definitely need that mirror)
- AutoDimming rear view mirror (inspected the overhead console, did not see the additional harness yet, but I did not find it the first time on the 2005 touring, keeping my fingers crossed) :unsure:
- Leather seats (very, very comfortable on the 2005 - my wife really liked that feature and me too! - dealer is gonmna do it for $1k)
- Uconnect (there is a kit for $299), might get it and install it, dunno yet - would like factory version better, but that costs a bunch
- AutoDimming Side Mirrors

anyone have any input on what I am looking to accomplish please chime in! :D

The 2005 touring did run well but was a bit slow and a gas hog. The 2007 is much faster and gets much better mpg on the highway (more torque and 6 gears). My experience with the car is that it is very reliable.
 

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Discussion Starter #4
You should probably post that list of possible mods in its own thread, where more people would read and respond to it.

On the research, will have results for the 2005 in early February, but with an asterisk for insufficient sample size. For May, I'd like to get rid of that asterisk and report on additional model years. Just need more participants.

Vehicle reliability research
 

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Discussion Starter #5
The latest results to TrueDelta's Vehicle Reliability Survey were recently posted. The 2005 Pacifica appears to have a better than average repair rate, while that for the 2007 Pacifica appears to be quite a bit worse than average.

In both cases, though, the sample sizes were marginal. So those results are asterisked, and visible only to members at the site.

I'd like to get rid of these asterisks and cover additional model years with the next update, in August. Just need more participants.

For the full set of results, and sign up to help (if you haven't already):

TrueDelta Vehicle Reliability Survey results
 

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Discussion Starter #6
Results have been posted for the 2005 and 2007. The 2005 has a reported repair rate that''s better than average, while the 2007 is much worse than average.

However, the sample sizes are small, so these results are asterisked and only visible to members on the site itself. It''s possible, even likely, that neither result in this case is accurate.

With more participants, I could report precise results for all model years. So hopefully more owners sign up and participate.

TrueDelta Vehicle Reliability Survey results
 

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Discussion Starter #7
The latest results for the Pacifica, in terms of successful repair trips per 100 vehicles per year:

2004: 83, about average

2005: 53, about average, maybe a bit better

2007: 132, much worse than average, thanks to a common problem with the new transmission

In all three cases the sample sizes are small, so these results are asterisked and only visible to members on the site.

With more participants, we could provide more precise results.

Results for the Chrysler Town & Country and Dodge Grand Caravan:

2001: 176, worse than average, marginal sample size

2002: 106, average, marginal sample size

2003: 74, average

2004: insufficient data

2005: 93 (uptick because of refresh?), average

2006: 68, average

2007: insufficient data

2008: 157, very high, good sample size

For the details on the Pacifica, minivans and 170+ other models, and to sign up to help out:

TrueDelta Vehicle Reliability Survey results
 

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Updated results next week. Sample sizes remain marginal for the Pacifica, so additional participants would be very helpful.

Chrysler repair rate research
Are you a statistics whiz? What is the population for this? I mean, how many Pacificas were made? And can you tell me the statistical significance goal you are shooting for? What sample size represents a 90% significance for the population of Pacifica production, scientifically speaking of course? And what significance does your current sample size represent? And the margin of error for each of the above?

Throwing our words like "Sizes remain marginal" sounds very English-y/Layman to me. Throw some science at us, man!
 

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Discussion Starter #9
Are you a statistics whiz? What is the population for this? I mean, how many Pacificas were made? And can you tell me the statistical significance goal you are shooting for? What sample size represents a 90% significance for the population of Pacifica production, scientifically speaking of course? And what significance does your current sample size represent? And the margin of error for each of the above?

Throwing our words like "Sizes remain marginal" sounds very English-y/Layman to me. Throw some science at us, man!
The size of the population is not part of the formula when calculating confidence intervals or required sample sizes ;) What does matter: the variance.

Also, "90% significance for the population" is, well, gibberish. I think you mean 90% confidence intervals, which means that if the same survey were conducted ten times, then nine times out of those ten the result would fall within the specified range. There's more than one variable here. You need to specify both the desired confidence interval, and the maximum width of the interval. For example, you might want 90% confidence that the actual number is no more than 10% different than the reported result.

I used to include confidence intervals in the results, but hardly anyone knows enough statistics to understand what they mean. Many people suggested I drop that information because it was too confusing to the typical site visitor, so I did.

The intervals are very wide for sample sizes I call "marginal," meaning in the high teens or low 20s. I don't consider a result "official" unless the sample size is at least 25, because that's where the results start to stabilize. Those with smaller sample sizes are asterisked, are not visible to non-members, and should not be used as anything but rough indicators.

Where would I like to be? I'd like a minimum sample size of 100, but we're not there yet in many cases. The way to get there is to start where we are, and keep building. For one model we already have a sample size of 220, and a number of others are already over 100. The Pacifica just isn't one of them. Would I like it to be? You bet.

Here's what we do have so far:

In terms of successful repair trips per 100 cars per year:

2004: 105, about average, but close to "worse than average"

2005: 47, better than average

2007: 109, worse than average, largely thanks to the new transmission

Sample sizes were small, even very small, for all three years. So, as noted above, these are just "ballpark" results.

A big thanks to everyone who has been helping. We'll have further updates in May, August, and November. With more participants, we could provide more precise information and cover all model years.

We now have a separate results page for each model that includes the results for competitors. The page for the Chrysler Pacifica:

Chrysler Pacifica reliability comparisons
 

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Discussion Starter #10
We have updated results for the Chrysler Pacifica. In terms of successful repair trips per 100 cars per year:

2004: 137, worse than average

2005: 69, about average, maybe a bit better

2007: 135, worse than average, largely thanks to the new transmission

Sample sizes were small, even very small, for all three years.

A big thanks to everyone who has been helping. We'll have further updates in August and November. With more participants, we could provide more precise information and cover all model years.

Chrysler Pacifica reliability comparisons
 

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Discussion Starter #11
We have updated results for the Chrysler Pacifica to include owner experiences through June 2009. In terms of successful repair trips per 100 cars per year:

2007: 93, worse than average, largely thanks to the new transmission

2006: 107, worse than average

2005: 85, about average

2004: 139, worse than average.

Sample sizes were small, even very small, for all four years.

A big thanks, once again, to this forum and everyone who has been helping. We'll have further updates in November and February. With more participants, we could provide more precise information and cover all model years.

Chrysler Pacifica reliability comparisons
 

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Discussion Starter #12
Updated results next month. Sample sizes a bit larger--the 2005 and 2007 are just four or five responses short of the minimum for a full result. So a few more participants would be very helpful.

Car reliability research
 

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Discussion Starter #13
We have updated results for the Chrysler Pacifica to include owner experiences through September 30, 2009. In terms of successful repair trips per 100 cars per year:

2007: 106, worse than average, largely thanks to the new transmission

2006: 79, about average

2005: 110, about average

2004: 165, worse than average.

Sample sizes were small for all four years, but some are now close to the minimum for a full result.

A big thanks, once again, to this forum and everyone who has been helping. We'll have further updates in February and May. With more participants, we could provide more precise information and cover all model years.

Chrysler Pacifica reliability comparisons
 

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Discussion Starter #15
We have updated results for the Chrysler Pacifica to include owner experiences through December 31, 2009. In terms of repair trips per 100 cars per year:

2007: 109

2006: 111

2005: 153

2004: 166

All are now worse than average. Sample sizes were small for all but the 2007.

A big thank you, once again, to everyone who has been helping. We'll have further updates in May and August. With more participants, we could provide more precise information and cover all model years.

Chrysler Pacifica reliability comparisons
 

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Discussion Starter #16
Recently enhanced the related repair history survey so that it can (optionally) be used as a personal car maintenance record.

As always, more participants would be helpful. Updated Car Reliability Survey results in May.

Car reliability research
 

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Discussion Starter #17
We have updated results for the Chrysler Pacifica to include owner experiences through March 31, 2010. In terms of repair trips per 100 cars per year:

2007: 84

2006: 136

2005: 147

2004: 179

The 2007 is now about average, while the others are worse than average. Sample sizes were small for all but the 2007.

A big thank you, once again, to everyone who has been helping. We'll have further updates in August and November. With more participants, we could provide more precise information and cover all model years.

Chrysler Pacifica reliability comparisons
 

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Discussion Starter #18
In a couple of weeks we'll start previewing the next set of results to participants. The preview results will be updated as responses come in--for me it's like watching the results of a presidential election, only four times a year.

My focus: how many model years will we be able to cover this time around? This depends on the number of owners that participate.

To help provide the best possible information on your year:

Car reliability research
 

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Discussion Starter #20
We have updated results for the Chrysler Pacifica to include owner experiences through June 30, 2010. Other sources of car reliability information won't cover the more recent months until the summer or even fall of next year.

Repair frequencies, in terms of repair trips per 100 cars per year:

2007: 101

2006: 120

2005: 124

2004: 141

All are worse than average. Small sample sizes for the 2004 and 2006.

Thank you, once again, to everyone who has been helping. We'll have further updates in November and February. With more participants, we could provide more precise information and cover all model years.

To see how competitors compare, and to sign up to help:

Chrysler Pacifica reliability comparisons
 
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