I wanted more up-to-date car reliability information that included actual repair rates. So in late 2005 I started getting people together to make this possible. TrueDelta now updates actual repair frequencies, not just dots, four times a year, to track cars closely as they age.

I've been posting in other model forums here, but not here in the XJ forum. Figured there weren't enough cars to draw from. But some XJ owners asked me to do more to get enough XJs involved. And it so happens that the 2004 is already halfway to the minimum sample size. So if owners here want to make some XJ reliability stats happen, they will happen. Ideally we'll cover all model years, including the new 2010+.

Participants simply report repairs the month after they occur on a one-page survey. When there are no repairs, they simply report an approximate odometer reading four times a year, at the end of each quarter.

To encourage participation, participants receive full access to all results, not just those for the XJ, for free.

For the details, and to sign up to help out:

Car reliability research

 

The 2004 is now only ten owners short of the minimum needed to get started, and other years are also closer.

Car reliability research

 

Just 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, with a preview for participants in mid-April.

Car reliability research

 

Anyone with the new XJ yet?

Hope to provide some reliability stats ahead of anyone else for it--just a matter of getting enough owners involved.

 

This should be an interesting thread, always want to know what the common faults are for this model.

 

We're now 2/3 of the way with the 2004, and other years are also getting closer.

 

Now 3/4 of the way with the 2004.

 

Now only four short of the minimum needed to get started with the 2004.

To help make this happen:

Car reliability research

 

I don't understand the premise of your whole "car research". You are rigging your whole study by not taking a random sample of the population.

 

"Rigging" isn't the right word, but I know what you mean.

I've found that collecting data going forward from the time someone joins rather than retrospectively (which is the way other surveys operate) effectively compensates for the lack of a random sample.

J.D. Power has a random sample, but their response rate tends to be in the low 20s. So the responses they actually gather could be far from random. The potential of non-response bias is much higher with a retrospective survey.

 

The 2004 is now only two cars short of the minimum and the 2005 is about halfway.

Updated stats for over 450 other cars next month.

 

The 2004 has been added to the survey. Thanks, guys.

Starting this month we have a new question to measure, as objectively as possible, the severity of a problem. Many people have been asking for reliability stats that weight problems by how severe they are, and once we have enough responses with the revised survey we'll start providing this.

Also this month: updated reliability stats.

As always, the more owners participate, the better the information we can provide to everyone. Looking forward to including the 2005 as well--it's currently halfway.

Car reliability research

 

Hoping to have an initial result for the 2004 with the May update, and the 2005 is now over halfway to getting started.

 

...fancy meeting you here. About 2006 models now?

 

Only six owners signed up for the 2006 so far. It's not uncommon to have the most interest from owners of the first model year, with less participation for each year afterwards, though the XJ trails off quicker than most.

 

We're currently a few responses short of having an initial result for the 2004 next month. But with a few weeks to go, we should get there.

I'd love to have full stats on all years from 1995 on. Especially the new car.

To help get your year included:

Car reliability research

 

We have an initial result for the XJ based on owner experiences through March 31, 2011.

With a repair frequency of 145 repairs per 100 cars per year, the 2004 XJ is worse than average. This stat is based on a very small sample size, though, so it's not precise.

Thank you, everyone who has been helping. We'll have further updates in August and November. With more participants, we could provide more precise results and cover all model years from 1995 on.

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

Jaguar XJ reliability ratings and comparisons

 

We've updated our car reliability stats for the XJ to include owner experiences through June 30, 2011.

With a repair frequency of 128 repairs per 100 cars per year, the 2004 XJ is worse than average. This stat is based on a small sample size, though, so it's not precise. It is encouraging that, with more participants this time, the reported repair frequency is a little lower.

We'll have further updates in November and February. With more participants, we could provide more precise results and cover all model years from 1995 on.

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

Jaguar XJ reliability ratings and comparisons

 

We've updated our car reliability stats for the XJ (on our redesigned site) to include owner experiences through September 30, 2011.

With a repair frequency of 129 repairs per 100 cars per year, the 2004 XJ is worse than average. This stat is based on a small sample size, though, so it's not precise. It is encouraging that, with more participants this time, the reported repair frequency is a little lower.

Thank you, once again, everyone who has been helping. We'll have further updates later this month and in May. With more participants, we could provide more precise results and cover all model years from 1995 on.

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

Jaguar XJ reliability ratings and comparisons

 

We've updated our car reliability stats for the XJ to include owner experiences through September 30, 2012.

With a repair frequency of 195 repairs per 100 cars per year, the 2004 XJ is worse than average. This stat is based on a very small sample size, though, so it's not precise.

We'll have further updates in February and May. We'd love to provide more precise stats and cover more model years--just a matter of getting more owners involved.

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

Jaguar XJ reliability ratings and comparisons