Porsche Boxster reliability -- let's get better info
 

A few owners have contacted me, asking to include the Boxster in the reliability survey conducted at TrueDelta.com. The key question: how common are IMS failures? In response, I've made getting the Boxster into the survey a top priority.

Here's how the research works: an email goes out once a month. If you have a repair, report it. If there have been no repairs, just report an approximate odometer reading at the end of the quarter--takes about 20-30 seconds four times a year.

We promptly update results quarterly, to closely track cars as they age.

Models are included in the survey once 25 owners sign up. Currently the 2000, 2005, and 2007 are each about halfway, and other years aren't far behind.

To encourage participation, free access to all results, not just those for the Boxster, is provided to everyone who signs up to participate.

Details:

Car reliability research

Sounds like a great idea. would you data include a repair history? Also, why not come out of the gate with the most grievous offenders; late 98's-early 99's ?

Regards, PK

I saw it on Babblers and signed up yesterday.

He needs 25 of each MY to have significant statistical data. I used to use 35 data points as minimum, but not sure which method he is using. And one of my colleages said 35 was not always required.

He didn't ask for any info I considered too private.

I'd love to have information on all model years. At this point, it's up to you guys. Whatever years we have enough data on, we'll provide results for.

It's possible to post repair histories even before a year is included in the main survey. There's a second survey with no minimum for simply posting repairs to the site. In the Repair Histories section responses to both surveys are merged.

The 25 number is a bare minimum for a reasonably stable result (one not likely to change much from update to update). You do have very wide confidence intervals with a sample of just 25. More is certainly better. We have sample sizes of 100+ for a few models, and a sample size over 230 for one.

With the Boxster and Cayman, we currently have 131 for all model years. Most for any year is 21 for the 2000. Up from about 75 when I first posted this thread, but we still have a way to go.

Details here:

Car reliability research

166 Boxsters and Caymans now signed up. A very good start considering the sales volumes. Thanks, guys.

But more remain needed if we're going to properly cover all model years. So far three model years are included in the main survey, and those are still close to the bare minimum sample size.

For the details, and to sign up to help get your year included:

Car reliability research

200 Boxster and Cayman owners now signed up. We hope to have some initial results in August, followed by some full results in November, but it's going to be tight. Six model years now either just above or just below the minimum sample size.

Car reliability research

Can you please explain to me who your are and of what value to you is this information. Is for a reliability study which is to be sold for a price or is it for your own information and the good of the Boxster community? Is anyone funding this research and what is their reason for funding. If these questions are answered I bet a lot more people , like myself , will be willing to participate. If it is a financial investment don't you think that offering some incentive of true value is appropo as we have what you want. Information has a value. Just my oponion. Ed

Sorry for the late response--the notification must have gone into my spam folder.

I conduct this research primarily for those who participate in it. Participants receive access to the results for all cars, not just the Boxster, for free--something that other reliability surveys do not offer. I do hope to benefit the Boxster community in general, so any reliability stats for the Boxseter will also be posted here.

I have been funding this research out of my own pocket. I justify it to my wife by saying there will eventually be some financial return, but we're not nearly there yet. My primary motivation has always been that I felt a need for more frequently updated, numeric reliability stats, and no one else was willing to provide such information to the general public. Sometimes if you want something done you need to do it yourself.

There are now 220 Boxster owners signed up to help. It looks like we'll have the first partial results in November. We will need larger sample sizes to provide stats for specific failure, like the IMS.

Car reliability research

Maybe it could be used in a class action lawsuit( that is if my engine ever implodes) :D

To be honest, I'd rather avoid this application, if only because it provides an incentive to distort the results.

244 Boxster and Cayman owners now signed up. Four model years are now in the survey, and another four are close to the minimum sample size. A good start, but more are needed to provide precise results for all model years.

Car reliability research

Where's Porsche?
 

I signed up. Went to "Car Reliability Comparisons" and found no entry for Porsche in the drop down menu. What's up?

I had the same issue, couldn't find Porsche anywhere. I guess I am tarded.

What's up is that we can't post any results in that area until we have enough people who've been participating for 3+ months. There's an inherent delay built into the survey process. To avoid possible sources of bias, it only collects data going forward.

With 273 owners signed up so far, we should start having results for some model years in November. The 1999, 2000, 2001, 2002, and 2005 are already in the survey, and the 2003, 2006, 2007, and 2008 are all close.

To sign up:

Car reliability research

To view repairs reported so far (not all of these will be included in the analysis):

Porsche Boxster repair histories

I saw the results yesterday for the 2001 Boxster...I knew the cars had maintenance issues but jeez. According to the number of times in the shop the Boxster is one of the worst. Good thing is I also own one of the most reliable, a 2005 4runner. I am going to try and get the IMS updated after the cold season.

You saw a preview of the November results that were only for participants in the survey.

The preview is based on data that has not been entirely cleaned, and responses are still coming in. We won't have an official result until November, and the figures could change.

I have not checked yet, but I doubt that many of the reported repairs have been for the IMS, or are even serious mechanical issues.

Also realize that the sample size is, as I type this, about 70% what we require for a full result. So even the November result will be a preliminary result. We should have a full result in February.

It is common for high reported repair rates to come down as the sample size grows. So I wouldn't get too wound up until we have that February result.

I do hope more owners will participate--the larger the sample size, the more precise the results will be.

We have our first reliability stats for the Boxster that include owner experiences through September 30, 2009. In terms of repair trips per 100 cars per year:

2005: 138, worse than average

2001: 189, worse than average

2000: 163, about average

1999: 91, better than average

In all four cases the sample sizes were a few cars short of the minimum needed for a full result, so these are asterisked and visible only to members on the site itself.

The result for the 1999 is clearly inconsistent with the others.

A big thank you to everyone who has been helping. We'll have more data and thus more precise results with the next update, in February. The more owners sign up and participate, the more precise these results will become.

Porsche Boxster reliability comparisons

Interesting.

Good job.

:cheers:

Thanks for the compliment, I appreciate it.

Updated results next month. I hope to have more consistent results this time. Much will depend on the number of participants. 317 owners signed up so far. A very good start, but clearly more remain needed.

Car reliability research

Later this month we'll have full results for four model years and partial results for two more.

The goal: full results for all model years.

Not yet signed up? Details here:

Car reliability research

We are all more than well read on the Boxster issues, still I'd like to add something my dad told me a long time ago that applies.

Any car is only as good as the mechanic that works on it and the owner's persistance to keep said vehicle maintained..

I'm not 100% sure of that....My Mom beat the crud out of her 96' Nissan Quest,only to change it's oil and filter on schedule....it lasted 240k miles without a hitch and would have lasted longer if it wasn't vandalized.

My Boxster has had weird annoying issues almost non-stop and it's pampered and hardly driven because of the weather.

There are always exceptions, coming from the car business I can tell you in general, beat & mistreat your car and you can expect it to be unreliable...

We have updated reliability stats for the Boxster and Cayman that include owner experiences through December 31, 2009. In terms of repair trips per 100 cars per year:

2008: 67, small sample size

2005: 103

2003: 125, small sample size

2002: 167, small sample size

2001: 125

2000: 129

1999: 133

With more data this time around, we're seeing more consistent results from year to year. Only the 2002 doesn't fit with the others.

The 2002 and 2003, both with small sample sizes, are worse than average. The other years, including those with decent sample sizes, are about average.

I'd like to report specifically on the IMS failure rate, but we will need more participants to do this. A small number of IMS failures have been reported.

A big thank you, once again, to everyone who has been helping. We'll have further updates, possibly including additional model years depending on the number of participants, in May and August.

Porsche Boxster reliability comparisons

354 Boxster and Cayman owners now signed up. A very good start, but more remain needed to provide precise results for all model years.

Not yet signed up? Details here:

Car reliability research

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

We have updated reliability stats for the Boxster and Cayman that include owner experiences through March 31, 2010. In terms of repair trips per 100 cars per year:

2008: 31, better than average

2006: 14, better than average, small sample size

2005: 71, about average

2003: 95, about average, small sample size

2002: 120, about average

2001: 129, about average

2000: 101, about average

1999: 129, about average

Note that these cars are driven an average of 5,000 miles a year, much less than the average car.

Fairly consistent results from year to year, with a clear improvement from 2005 to 2006. The results for the 2000 and 2006 might be a bit lower than they should be, judging from the results for other model years.

I'd like to report specifically on the IMS failure rate, but we will need more participants to do this. So far, with 180 986s participating for an average of about six months, only two IMS failures have been reported, and none since last August.

A big thank you, once again, to everyone who has been helping. We'll have further updates, possibly including additional model years depending on the number of participants, in August and November.

truedelta.com/car-reliability.php?stage=pt&bd=Porsche&mc=239

I have only owned the car for 8 mos, but I can say when youre driving a boxster, there is a noticeable difference vs a S2000 or Miata. Reliability is another story, but in my opinion it is just not comparable to put the other two in the same grouping

Are there cars compared here, earlier in the thread?

On the site comparisons are driven by which cars users compare when running price comparisons.

In a couple of weeks we'll start previewing the next set of results to participants. The preview results are actually 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? It depends entirely on the number of owners that participate.

To help provide the best possible information on your year:

truedelta.com/reliability.php

Updated stats in about two weeks. 417 owners now signed up. Very good, but more remain needed to fully cover all years.

To help provide better information on your year:

truedelta.com/reliability.php

We have updated reliability stats for the Boxster and Cayman that 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:

2008: 36, better than average

2006: 47, better than average

2005: 49, better than average

2004: 67, about average, small sample size

2003: 94, about average, small sample size

2002: 118, about average

2001: 115, about average

2000: 92, better than average

1999: 117, about average

Important note: these cars are only driven an average of 5,500 miles a year, about half as much as the average car. No adjustment has been made for this.

Very consistent results from year to year. The result for the 2000 might be a bit lower than it should be, judging from the results for other model years.

I'd like to report specifically on the IMS failure rate, but we will need more participants to do this. So far, with 180 986s participating for an average of about six months, only four IMS failures have been reported, two of them over a year ago.

Thank you, once again, to everyone who has been helping. We'll have further updates, possibly including additional model years depending on the number of participants, in November and February.

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

truedelta.com/car-reliability.php?stage=pt&bd=Porsche&mc=239

We have updated reliability stats for the Boxster and Cayman that include owner experiences through September 30, 2010. Other sources of car reliability information won't cover the months since April until the summer or even fall of next year.

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

2008: 59, about average

2007: 61, about average, small sample size

2006: 53, better than average

2005: 45, better than average

2004: 71, about average, small sample size

2003: 55, better than average

2002: 92, about average

2001: 98, better than average

2000: 69, better than average

1999: 156, worse than average, small sample size

Important note: these cars are only driven an average of 5,500 miles a year, about half as much as the average car. No adjustment has been made for this.

I'd like to report specifically on the IMS failure rate, but we will need more participants to do this. A few more failures have been reported recently, but still about two to three per 100 cars in the past year.

Thank you, once again, to everyone who has been helping. We'll have further updates, possibly including additional model years depending on the number of participants, in February and May.

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

truedelta.com/car-reliability.php?stage=pt&bd=Porsche&mc=239

Lucky i guess
 

My 1998my boxie has not had one issue since I bought the car over 6 months ago...it is my dd and I have had nothing but fun!!!I have replaced tires and coolant cap(which I still add a small bit of coolant every 3 weeks) but other than that...no probs...oh..my mileage is 92,xxx and is a strong tip!!!

Now I know that is not a long time to own a car, but as I keep her "fresh" I can't see anything that bad! And if I have a problem, then I know that I can get help on this wonderful site. :D Oh wait...I do have one issue...The lever for the trunks does not unlock anymore...but that's okay...I use the small screwdriver method,lol :D

We have some new pages that display all reported repairs by problem area:

truedelta.com/car-problem-descriptions.php?stage=pt&bd=Porsche&mc=239&my=200 2&gc=

From this page it's possible to select a different model year or specify a problem area.

We have updated reliability stats for the Boxster and Cayman that include owner experiences through December 31, 2010.

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

2008: 39, better than average

2007: 59, about average

2006: 49, better than average

2005: 54, better than average

2004: 88, about average, small sample size

2003: 58, better than average

2002: 124, about average

2001: 104, about average

2000: 90, better than average

1999: 106, about average, small sample size

Important note: these cars are only driven an average of 5,500 miles a year, about half as much as the average car. No adjustment has been made for this.

Six IMS failures were reported for the 2010 calendar year, most of them for 2004-2005 model year cars (with the 2005 being a 987 rather than a 986). Some of these failures might have occurred before the car was enrolled, in which case they would not be included in the above stats. So this count might err on the high side. The total sample size for 1999-2005 is 220 cars. No IMS failures have been reported for cars 2006 and newer.

Thank you, once again, to everyone who has been helping. We'll have further updates, possibly including additional model years depending on the number of participants, in May and August.

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

Porsche Boxster reliability ratings and comparisons

Very cool data collection! I entered my newly acquired 2002. All the little things I'm doing to baseline are probably skewing things a little bit.

Very interested to see how the trends continue.

just curious, but is there any validation of the data being submitted? maybe VIN number requirement of person submitting the claims?

Garbage in, garbage out! What can I say, I'm an analyst.

The problem with such validation is that hardly anyone would go through the effort to provide a VIN. The quality of the resulting information would be harmed far more through reduced sample sizes than helped by making it harder for people to report on cars that don't actually exist. Especially since there's never been any evidence of the latter.

The big problem is getting people to report on the cars they do have, not keeping them from reporting on cars they don't actually have.

signed up for this back in September when i bought my car. Good work!

Ditto. Incase of exhange in ownership.