Vehicle Reliability Survey results
09-26-2008, 10:30 AM
#1
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Vehicle Reliability Survey results
Wanting better reliability information, in late 2005 I started conducting a reliability survey at TrueDelta.com.
So far 386 Maxima and I-Series owners have signed up to participate. Which is a good start, but more are needed to sufficiently cover all model years from 1995 on.
So far we have results for two years of the 5th gen Maxima. But the sample sizes are marginal, so these results are asterisked and only visible to participants on the site itself. Based on this limited amount of data, the 2000s appear to have a worse than average repair rate--about 188 repair trips per 100 cars per year--and the 2001s an average repair rate--119 repair trips per 100 cars per year. In both cases the average odometer reading is nearly 100k.
I suspect the results would be closer together with small sample sizes. But we might also be seeing a lingering "first model year" effect.
The full set of results, with another update coming in November:
Vehicle reliability research
So far 386 Maxima and I-Series owners have signed up to participate. Which is a good start, but more are needed to sufficiently cover all model years from 1995 on.
So far we have results for two years of the 5th gen Maxima. But the sample sizes are marginal, so these results are asterisked and only visible to participants on the site itself. Based on this limited amount of data, the 2000s appear to have a worse than average repair rate--about 188 repair trips per 100 cars per year--and the 2001s an average repair rate--119 repair trips per 100 cars per year. In both cases the average odometer reading is nearly 100k.
I suspect the results would be closer together with small sample sizes. But we might also be seeing a lingering "first model year" effect.
The full set of results, with another update coming in November:
Vehicle reliability research
12-03-2008, 12:02 PM
#2
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It's been three months, so the results for the Nissan Maxima have been updated again.
Repair rates, in terms of successful repair trips per 100 vehicles per year:
2000: 214, worse than average
2001: 124, about average
Sample sizes were larger, but still marginal. I thought the difference between the model years would narrow, but it didn't. That said, with more participants, we could provide more precise results and include more model years.
For the full set of results, and to sign up to help:
TrueDelta Vehicle Reliability Survey results
Repair rates, in terms of successful repair trips per 100 vehicles per year:
2000: 214, worse than average
2001: 124, about average
Sample sizes were larger, but still marginal. I thought the difference between the model years would narrow, but it didn't. That said, with more participants, we could provide more precise results and include more model years.
For the full set of results, and to sign up to help:
TrueDelta Vehicle Reliability Survey results
12-04-2008, 08:05 PM
#3
I've seen trudelta data on other car sites as well, and am not confident in the results. most people who report are people with problems, just like most people don't post on the org saying "hey everything is just fine with my car." It's a nice idea, but it's like an exit poll at an election...not very accurate.
12-04-2008, 10:39 PM
#4
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This is a common misconception.
We use a unique survey process to prevent exactly this sort of bias. Unlike other surveys we collect data going forward, so people cannot report old problems on the main survey.
Because pretty much every other survey is a one-time deal asking people about things that happened before they signed up to participate--a process that can and often does lead to the problem you describe--people assume that ours is the same way. But it's not.
Instead, people sign up to report repairs that occur afterwards, not problems that have already happened.
This process has been working very well--as seen in the actual results. In any given month, only about one in ten participants reports a repair, and this includes things that don't count as repairs in the analysis (like brake pads and recalls). The other nine in ten simply report an approximate odometer reading, so we know that they are participating but had no repair the previous month. Some newer cars have reported repair rates near zero. If only people with problems participated, this proportion would be ten in ten.
The actual problem in most cases is simply not having enough people for most models. But that's getting fixed : )
We use a unique survey process to prevent exactly this sort of bias. Unlike other surveys we collect data going forward, so people cannot report old problems on the main survey.
Because pretty much every other survey is a one-time deal asking people about things that happened before they signed up to participate--a process that can and often does lead to the problem you describe--people assume that ours is the same way. But it's not.
Instead, people sign up to report repairs that occur afterwards, not problems that have already happened.
This process has been working very well--as seen in the actual results. In any given month, only about one in ten participants reports a repair, and this includes things that don't count as repairs in the analysis (like brake pads and recalls). The other nine in ten simply report an approximate odometer reading, so we know that they are participating but had no repair the previous month. Some newer cars have reported repair rates near zero. If only people with problems participated, this proportion would be ten in ten.
The actual problem in most cases is simply not having enough people for most models. But that's getting fixed : )
Last edited by mkaresh; 12-04-2008 at 10:46 PM.
01-14-2009, 09:45 PM
#6
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It's been three months, so the results for the Nissan Maxima have been updated again.
Repair rates, in terms of successful repair trips per 100 vehicles per year:
2000: 214, worse than average
2001: 124, about average
Sample sizes were larger, but still marginal. I thought the difference between the model years would narrow, but it didn't. That said, with more participants, we could provide more precise results and include more model years.
For the full set of results, and to sign up to help:
TrueDelta Vehicle Reliability Survey results
Repair rates, in terms of successful repair trips per 100 vehicles per year:
2000: 214, worse than average
2001: 124, about average
Sample sizes were larger, but still marginal. I thought the difference between the model years would narrow, but it didn't. That said, with more participants, we could provide more precise results and include more model years.
For the full set of results, and to sign up to help:
TrueDelta Vehicle Reliability Survey results
01-15-2009, 09:48 AM
#7
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Sorry it's taken so long. Right now we're two months of data short of having a partial result for the 2002 in early February. So we'll probably get there.
I've created the system and put it in place. The amount of information we have on a car and how soon we have it is now entirely up to owners.
Car reliability research
I've created the system and put it in place. The amount of information we have on a car and how soon we have it is now entirely up to owners.
Car reliability research
02-15-2009, 05:17 AM
#8
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We have updated results for the Nissan Maxima. In terms of successful repair trips per 100 cars per year:
2000: 180, worse than average, 106,000 average odometer
2001: 132, average, 103,000 average odometer
2002: 37, better than average, 77,500 average odometer
Sample sizes were small, even very small, so these results are asterisked and only visible to members on the site. With more participants, it's likely that the reported repair rate for the 2000 would be lower and that for the 2002 would be higher. There are far fewer average miles on the 2002s in the survey, which explains some of the difference.
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 Nissan Maxima:
Nissan Maxima reliability comparisons
2000: 180, worse than average, 106,000 average odometer
2001: 132, average, 103,000 average odometer
2002: 37, better than average, 77,500 average odometer
Sample sizes were small, even very small, so these results are asterisked and only visible to members on the site. With more participants, it's likely that the reported repair rate for the 2000 would be lower and that for the 2002 would be higher. There are far fewer average miles on the 2002s in the survey, which explains some of the difference.
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 Nissan Maxima:
Nissan Maxima reliability comparisons
03-08-2009, 03:10 PM
#9
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03-08-2009, 04:15 PM
#10
mkaresh, would you mind sharing the actual test data with us to prove the validity of this claim? I am confident that you have the t-tests available (or ANOVA, since were taking from about the same table, ya know? ) to prove the statistical significance of this claim. Also, please list your null hypothesis and the control group against which the Maxima was compared. Thank-ya. 
Last edited by Metal Maxima; 03-08-2009 at 04:17 PM.
03-09-2009, 09:59 AM
#11
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mkaresh, would you mind sharing the actual test data with us to prove the validity of this claim? I am confident that you have the t-tests available (or ANOVA, since were taking from about the same table, ya know? ) to prove the statistical significance of this claim. Also, please list your null hypothesis and the control group against which the Maxima was compared. Thank-ya.
We've got a great process in place, but the sample sizes for the Maxima need to be larger before the types of analyses you're looking for would be worthwhile. We do compute the standard errors, and with sample sizes as small as they are for the Maxima the CIs are wide. Sample sizes are 100+ for some other models.
Control group
That would be the car owners who are getting the placebo... Do you do much (any?) survey research where the design includes a control group?
06-06-2009, 11:49 AM
#12
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We have updated results for the Maxima to include owner experiences through March 2009. In terms of successful repair trips per 100 cars per year:
2002: 46, better than average
2001: 123, about average
2000: 130, about average
Sample sizes range from small to just a couple short of the minimum for a full result, so these are all just partial results. The 2000, and 2001 had the largest sample sizes, so those are probably the most accurate.
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.
Nissan Maxima reliability comparisons
2002: 46, better than average
2001: 123, about average
2000: 130, about average
Sample sizes range from small to just a couple short of the minimum for a full result, so these are all just partial results. The 2000, and 2001 had the largest sample sizes, so those are probably the most accurate.
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.
Nissan Maxima reliability comparisons
09-06-2009, 10:55 AM
#13
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We have updated results for the Maxima and I30/I35 to include owner experiences through June 2009. In terms of successful repair trips per 100 cars per year:
2003: 18, very small sample size, actual repair rate likely higher but still better than average
2002: 39, better than average, small sample size
2001: 125, about average, marginal sample size, average odometer now over 100k
2000: 108, about average, marginal sample size
A big thanks to everyone who has been helping. We'll have further updates in November and February. The more owners participate, the better the information we can provide.
Nissan Maxima reliability comparisons
2003: 18, very small sample size, actual repair rate likely higher but still better than average
2002: 39, better than average, small sample size
2001: 125, about average, marginal sample size, average odometer now over 100k
2000: 108, about average, marginal sample size
A big thanks to everyone who has been helping. We'll have further updates in November and February. The more owners participate, the better the information we can provide.
Nissan Maxima reliability comparisons
10-11-2009, 11:24 AM
#14
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Updated results next month. Sample sizes will be larger, but still not large enough to avoid the asterisks. We're currently two responses short of a full result for the 2000, so it might get there. A few more people per model year would be very helpful.
Car reliability research
Car reliability research
11-15-2009, 09:50 AM
#17
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Updated results again later this month.
We're going to start providing new stats for the odds of requiring no repairs and the odds of getting a lemon. Something no one, including CR, has ever provided before. These require larger sample sizes, so additional participants would be helpful.
For the details, and to sign up:
Car reliability research
We're going to start providing new stats for the odds of requiring no repairs and the odds of getting a lemon. Something no one, including CR, has ever provided before. These require larger sample sizes, so additional participants would be helpful.
For the details, and to sign up:
Car reliability research
11-16-2009, 05:56 PM
#18
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I've seen trudelta data on other car sites as well, and am not confident in the results. most people who report are people with problems, just like most people don't post on the org saying "hey everything is just fine with my car." It's a nice idea, but it's like an exit poll at an election...not very accurate.
12-22-2009, 08:37 AM
#19
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Consider this: about two-thirds of survey participants report no repairs for the past year. If anything, people are reporting fewer problems than I expected, not more as you suggest. The prospective research design no doubt helps--it excludes old repairs from the analysis.
12-22-2009, 08:38 AM
#20
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We have updated results for the Maxima and I30/I35 to include owner experiences through September 30, 2009. In terms of repair trips per 100 cars per year:
2003: 93, about average
2002: 50, better than average
2001: 137, about average
2000: 93, better than average
Small sample sizes except for the 2000.
A big thanks 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.
Nissan Maxima reliability comparisons
2003: 93, about average
2002: 50, better than average
2001: 137, about average
2000: 93, better than average
Small sample sizes except for the 2000.
A big thanks 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.
Nissan Maxima reliability comparisons
12-28-2009, 04:32 PM
#22
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It blows me away that people think their cars are a pos when something brakes.
12-29-2009, 06:45 AM
#23
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Feel free to compile a list of specific items and that will be data.
mkaresh - my 2001 20AE is probably about average, though dealership/Nissan records would probably put it higher since I do most of my own work.
Not at all sure that I can contribute to the survey site from work (due to corporate internet filtering). I can only remember one dealership visit early on for a rough running on cold start issue. For my part, a battery or two, ditto for alternator, one O2 sensor, brake pads/front rotors (only once), coolant replacement, and an inop driver seat fore/aft adjustment. On the to-do list, VIAS, inop driver seat cushion adjustment, driver seating surface wear/tear, and a dead ABS wheel sensor (that at ~$150 for the part I may simply continue to ignore). Between 90k and 100k miles.
Norm
Last edited by Norm Peterson; 04-06-2010 at 03:50 AM. Reason: spelling/wrong word
01-27-2010, 08:46 AM
#24
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The main survey only collects data going forward, to minimize potential distortions. You sign up, I send an email with a link to the quick survey once a month, and unless you have a repair earlier a response is only needed every third month. If you have no repair to report, the response is only an approximate odometer reading.
Perceptions of reliability probably vary even more than reliability does. Some people get upset about a single small problem, while others will write off ten such problems as "minor." So we have people report all repairs beyond routine maintenance, to get objective results.
Car reliability research
Perceptions of reliability probably vary even more than reliability does. Some people get upset about a single small problem, while others will write off ten such problems as "minor." So we have people report all repairs beyond routine maintenance, to get objective results.
Car reliability research
03-02-2010, 09:58 AM
#25
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We have updated results for the Maxima and I30/I35 to include owner experiences through December 31, 2009. In terms of repair trips per 100 cars per year:
2003: 112, small sample
2002: 125
2001: 116
2000: 113
Now very consistent from year to year, and all about average.
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.
Nissan Maxima reliability comparisons
2003: 112, small sample
2002: 125
2001: 116
2000: 113
Now very consistent from year to year, and all about average.
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.
Nissan Maxima reliability comparisons
04-05-2010, 11:56 AM
#26
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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
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
04-05-2010, 03:39 PM
#27
ya know i could honestly careless what a website thinks based on surveys ive had my car almost 3 years and replaced a radiator starter mass air flow brakes and muffler.....that being said with 198k on my car and 1000 miles a week worth of driving that website can pound sand IMO
06-16-2010, 06:13 AM
#28
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We have updated results for the Maxima and I30/I35 to include owner experiences through March 31, 2010. In terms of repair trips per 100 cars per year:
2003: 118
2002: 114
2001: 109
2000: 145
All about average.
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.
Nissan Maxima reliability comparisons
2003: 118
2002: 114
2001: 109
2000: 145
All about average.
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.
Nissan Maxima reliability comparisons
09-01-2010, 09:01 AM
#29
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We have updated results for the Maxima and I30/I35 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:
2003: 143, worse than average
2002: 150, worse than average
2001: 110, about average
2000: 144, about average
It's not clear why the 2002 and 2003 are as high as they are.
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:
Nissan Maxima reliability comparisons
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:
2003: 143, worse than average
2002: 150, worse than average
2001: 110, about average
2000: 144, about average
It's not clear why the 2002 and 2003 are as high as they are.
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:
Nissan Maxima reliability comparisons
11-19-2010, 08:45 AM
#33
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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.
Car reliability research
Also this month: updated reliability stats.
As always, the more owners participate, the better the information we can provide to everyone.
Car reliability research
01-29-2011, 09:16 AM
#34
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We have updated results for the Maxima and I30/I35 to include owner experiences through September 30, 2010.
Repair frequencies, in terms of repair trips per 100 cars per year:
2003: 91, about average
2002: 152, worse than average
2001: 104, about average
2000: 126, about average
It's not clear why the 2002 is so high, possibly a fluke.
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:
Nissan Maxima reliability ratings and comparisons
Repair frequencies, in terms of repair trips per 100 cars per year:
2003: 91, about average
2002: 152, worse than average
2001: 104, about average
2000: 126, about average
It's not clear why the 2002 is so high, possibly a fluke.
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:
Nissan Maxima reliability ratings and comparisons
01-29-2011, 05:21 PM
#35
I've had only two repairs in the last 18 months with my '02. Replaced the pre-cats and the passenger side engine mount. Not bad for a car with 194,595-which, sad to say is the car's final mileage due to that scumbag drunk who ran a light and totaled it.
04-08-2011, 11:28 AM
#36
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We have updated results for the Maxima to include owner experiences through December 31, 2010. Other sources of car reliability information won't cover the months since April until the summer or even fall of this year.
Repair frequencies, in terms of repair trips per 100 cars per year:
2010: 34
2009: 13
Both are better than average. The difference between the two years is likely due to random error than any actual difference--even the 2010 is fairly low.
Thank you, once again, to everyone who has been helping. We'll have further updates in May and August.
To see how competitors compare, and to sign up to help:
Nissan Maxima reliability ratings and comparisons
Repair frequencies, in terms of repair trips per 100 cars per year:
2010: 34
2009: 13
Both are better than average. The difference between the two years is likely due to random error than any actual difference--even the 2010 is fairly low.
Thank you, once again, to everyone who has been helping. We'll have further updates in May and August.
To see how competitors compare, and to sign up to help:
Nissan Maxima reliability ratings and comparisons
07-15-2011, 10:39 AM
#37
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We have updated our reliability stats for the Maxima and I30/I35 to include owner experiences through March 31, 2011.
Repair frequencies, in terms of repair trips per 100 cars per year:
2003: 63, better than average, small sample size
2002: 105, about average
2001: 97, better than average
2000: 109, about average
We'll have further updates in August and November. With more participants, we could provide more precise information and fully cover all model years.
To see how competitors compare, and to sign up to help improve this information:
Nissan Maxima reliability ratings and comparisons
Repair frequencies, in terms of repair trips per 100 cars per year:
2003: 63, better than average, small sample size
2002: 105, about average
2001: 97, better than average
2000: 109, about average
We'll have further updates in August and November. With more participants, we could provide more precise information and fully cover all model years.
To see how competitors compare, and to sign up to help improve this information:
Nissan Maxima reliability ratings and comparisons
10-13-2011, 10:02 AM
#38
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We have updated results for the Maxima and I30/I35 to include owner experiences through June 30, 2011.
Repair frequencies, in terms of repair trips per 100 cars per year:
2003: 47, better than average, small sample size
2002: 105, about average
2001: 100, about average
2000: 144, about average
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 improve this information:
Nissan Maxima reliability ratings and comparisons
Repair frequencies, in terms of repair trips per 100 cars per year:
2003: 47, better than average, small sample size
2002: 105, about average
2001: 100, about average
2000: 144, about average
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 improve this information:
Nissan Maxima reliability ratings and comparisons
10-13-2011, 01:17 PM
#39
I think this is a great idea. The more information from different sources that's available to consumers, the better.
I just signed up, enrolled my '01 Maxima and my '05 4Runner, but received emails that my vehicles are already included in the survey....
BTW, maxima.org (and 4Runner.org, for that matter) are not listed for choosing which forum we use.
I just signed up, enrolled my '01 Maxima and my '05 4Runner, but received emails that my vehicles are already included in the survey....
BTW, maxima.org (and 4Runner.org, for that matter) are not listed for choosing which forum we use.
10-13-2011, 05:13 PM
#40
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I think this is a great idea. The more information from different sources that's available to consumers, the better.
I just signed up, enrolled my '01 Maxima and my '05 4Runner, but received emails that my vehicles are already included in the survey....
BTW, maxima.org (and 4Runner.org, for that matter) are not listed for choosing which forum we use.
I just signed up, enrolled my '01 Maxima and my '05 4Runner, but received emails that my vehicles are already included in the survey....
BTW, maxima.org (and 4Runner.org, for that matter) are not listed for choosing which forum we use.
These were probably just emails confirming that you'd enrolled the cars and letting you know that they're among the models included in the survey.
Long ago I contacted forums asking for permission to list them as partners. Some got back to me, others did not.