Porsche Boxster reliability -- let's get better info

[mkaresh]

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

[pk2]

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

[70Sixter]

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.

[mkaresh]

Originally Posted by pk2

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 ?

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

[mkaresh]

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

[mkaresh]

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

[cvhs18472]

Originally Posted by mkaresh

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

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

[mkaresh]

Originally Posted by cvhs18472

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

[mptoledo]

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

[mkaresh]

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

[mkaresh]

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

[mkaresh]

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

[mkaresh]

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

[dennis]

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

[mkaresh]

Originally Posted by dennis

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

[mkaresh]

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

[mkaresh]

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

[mkaresh]

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

[mkaresh]

We have updated reliability stats for the Boxster and Cayman that include owner experiences through September 30, 2011.

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

2008: 28, better than average

2007: 75, about average, might be high because final year of standard warranty

2006: 39, better than average

2005: 72, about average

2004: 44, better than average, small sample size

2003: 53, better than average

2002: 135, about average

2001: 97, better than average

2000: 120, about average

1999: 71, better than average, small sample size

We have two additional statistics, "Nada-odds" and "Lemon-odds," to indicate the percentage of cars with no repairs in the past year and those that required 3+ trips to the repair shop.

For the years where we have enough data for these:

2008: 67, < 1

2006: 65, < 1

2001: 51, 11

Porsche Boxster Lemon-odds and Nada-odds

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).

No IMS failures have been reported for cars 2006 and newer.

No IMS failures have been reported for any model year since the beginning of 2011, with over 200 owners of 1999-2005 cars participating.

Rear main seal and air/oil separator repairs are far more common.

Thank you, once again, to 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.

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

Porsche Boxster reliability ratings and comparisons

[mkaresh]

We have updated reliability stats for the Boxster and Cayman that include owner experiences through December 31, 2011.

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

2008: 31, better than average

2007: 72, about average, might be high because final year of standard warranty

2006: 49, better than average

2005: 56, better than average

2004: 16, better than average, small sample size

2003: 42, better than average

2002: 97, better than average

2001: 95, better than average

2000: 100, about average

1999: 60, better than average

We have two additional statistics, "Nada-odds" and "Lemon-odds," to indicate the percentage of cars with no repairs in the past year and those that required 3+ trips to the repair shop.

For the years where we have enough data for these:

2008: 72, < 1

2006: 71, 4

2005: 49, 4

2001: 42, 4

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).

No IMS failures have been reported for cars 2006 and newer.

No IMS failures have been reported for any model year since the beginning of 2011, with over 200 owners of 1999-2005 cars participating.

Rear main seal and air/oil separator repairs remain far more common.

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.

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

Porsche Boxster reliability ratings and comparisons

Porsche Boxster repair odds