RX-8 Reliability - Engine Data Survey
08-04-2010, 07:49 PM
#51
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Agreed shady, alot of people here are either past warranty and don't care, in warranty and don't care, voided their warranty willingly and don't care, etc... But I have to add that layer of protection making the data anonymous to protect those that don't want to give Mazda an excuse to void the warranty for "making a statement on a forum board". Without it, the fear of Mazda finding out how they responded could either keep them away, or cause them to hedge their responses. Either one is a detriment to the data.
I've got 27 engine IDs handed out so far, but only 9 responses. Gonna take time to build them i think.
I've got 27 engine IDs handed out so far, but only 9 responses. Gonna take time to build them i think.
08-04-2010, 10:12 PM
#54
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See 2nd post for example report from the first 10 responses. So many way to look at the data, most of those ways aren't even reasonably possible before 50 or so responses.
This is just a simple cross tab based on engine replaced yes or no, and the rest of the questions.
This is just a simple cross tab based on engine replaced yes or no, and the rest of the questions.
08-05-2010, 09:57 AM
#64
An unintended consequence
The survey questions are nicely detailed and well thought out. That's good. Alas, I fear the survey also happens to follow the law of unintended consequences:
if I were someone considering buying an RX-8, and I found my way to this forum to research the car, and I opened this thread and saw the survey questions, I'd run from here and look for another car. Any other car - which would undoubtedly be more reliable than one of these "rotary" RX-8s.
Which is unfortunate because if, say, 94% of RX-8 engines running around out there are reliable, I'd never guess that looking at the questions in this survey. On the contrary, I'd think "holy cow, those RX-8 engines must be a real headache! Thank god I found this before I bought one!"
Of course, nowhere in the survey is there anything that says RX8 engines are unreliable. But I think that's the impression the survey creates - even if it's not true.
Imagine I came to your house and asked to interview you, and spent 20 minutes asking you various questions about how many wives you've had, how often you beat your current wife, as well as your previous wives. All perfectly legitimate questions for someone studying wife beating.
Now let's say a neighbor who just moved in heard you were interviewed about wife beating. What do you guess they would think? Even if you'd only been married to one woman and never beat her?
Not a big deal. A thorough survey, for a change, is a nice idea. But I do think it'll give potential owners second thoughts.
Maybe there could be a little disclaimer at the beginning of the thread? Something like "Note: Most RX-8 engines are reliable and run trouble-free. But some have experienced engine problems. This detailed survey is designed to find out more about those RX-8 engines that have had problems."
Just a thought.
if I were someone considering buying an RX-8, and I found my way to this forum to research the car, and I opened this thread and saw the survey questions, I'd run from here and look for another car. Any other car - which would undoubtedly be more reliable than one of these "rotary" RX-8s.
Which is unfortunate because if, say, 94% of RX-8 engines running around out there are reliable, I'd never guess that looking at the questions in this survey. On the contrary, I'd think "holy cow, those RX-8 engines must be a real headache! Thank god I found this before I bought one!"
Of course, nowhere in the survey is there anything that says RX8 engines are unreliable. But I think that's the impression the survey creates - even if it's not true.
Imagine I came to your house and asked to interview you, and spent 20 minutes asking you various questions about how many wives you've had, how often you beat your current wife, as well as your previous wives. All perfectly legitimate questions for someone studying wife beating.
Now let's say a neighbor who just moved in heard you were interviewed about wife beating. What do you guess they would think? Even if you'd only been married to one woman and never beat her?
Not a big deal. A thorough survey, for a change, is a nice idea. But I do think it'll give potential owners second thoughts.
Maybe there could be a little disclaimer at the beginning of the thread? Something like "Note: Most RX-8 engines are reliable and run trouble-free. But some have experienced engine problems. This detailed survey is designed to find out more about those RX-8 engines that have had problems."
Just a thought.
Last edited by New Yorker; 08-05-2010 at 10:07 AM.
08-05-2010, 10:06 AM
#65
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I agree the Rotary has gotten a bad rap and this does not help but that is what I would like to know, how unreliable is the Renesis? I myself am on my 3rd engine in 114,000 miles and I take very good care of my vehicles.
I have seen numbers thrown around here and speculation that the overall number of replacement engines is small. But I mean, they did have to build a plant just to rebuild them. Personally I think the number is significant because of the number of replacements I have had and because I have met many people with RX-8's that have had engine failures. Not to mention the amount of replacements that have been done at my dealer and from what another member I know who is a Mazda tech at a local dealer here has told me.
Honestly, I know more RX-8 owners that have had engine replacements than I do that have not. And strangely enough, not all of these people frequent this board and many are not really RX-8 enthusiasts either.
many people just buy the car to drive and nothing more. I know a guy who has owned two RX-8's and one day when I was looking under his hood and he asked me, "Where is the throttle cable?"
I have seen numbers thrown around here and speculation that the overall number of replacement engines is small. But I mean, they did have to build a plant just to rebuild them. Personally I think the number is significant because of the number of replacements I have had and because I have met many people with RX-8's that have had engine failures. Not to mention the amount of replacements that have been done at my dealer and from what another member I know who is a Mazda tech at a local dealer here has told me.
Honestly, I know more RX-8 owners that have had engine replacements than I do that have not. And strangely enough, not all of these people frequent this board and many are not really RX-8 enthusiasts either.
many people just buy the car to drive and nothing more. I know a guy who has owned two RX-8's and one day when I was looking under his hood and he asked me, "Where is the throttle cable?"
Last edited by 9krpmrx8; 08-05-2010 at 10:16 AM.
08-05-2010, 10:12 AM
#66
I need to get my build date off my car and I will complete the survey. My car came out to Ca on 96k was bought at an auction in MN where it spent half its life the first half was in SC I believe.
It would be interesting to see if location of the vehicle affected the life of it. Those of us with used cars would need to purchase a carfax report.
I imagine most of us with engine failure live in warmer climates.
It would be interesting to see if location of the vehicle affected the life of it. Those of us with used cars would need to purchase a carfax report.
I imagine most of us with engine failure live in warmer climates.
08-05-2010, 10:15 AM
#67
From Wikipedia:
Evidence, which may itself be true and verifiable, used to deduce a conclusion which does not follow from it, usually by generalizing from an insufficient amount of evidence. For example "my grandfather smoked like a chimney and died healthy in a car crash at the age of 99" does not disprove the proposition that "smoking markedly increases the probability of cancer and heart disease at a relatively early age". In this case, the evidence may itself be true, but does not warrant the conclusion.
In both cases the conclusion is unreliable; it may not be untrue, but it doesn't follow from the "evidence".
This is the very reason why people do surveys with a random sampling of responses. Which this is not.
Last edited by New Yorker; 08-05-2010 at 10:21 AM.
08-05-2010, 10:21 AM
#68
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No, my uneducated guess would be 20% or so. We have 5 or 6 mazda dealers here in San Antonio and if one dealers has done a hundred or so replacements then it is a significant number I would say. Another member here is a Tech at one of the smaller dealers in the area and within the first month or so he worked there, he did a handful of engine replacements. and he is seeing more and more 2005's and 2006's so it is not specific to the 2004 RX-8's either.
08-05-2010, 10:24 AM
#69
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The survey questions are nicely detailed and well thought out. That's good. Alas, I fear the survey also happens to follow the law of unintended consequences:
<snip>
Maybe there could be a little disclaimer at the beginning of the thread? Something like "Note: Most RX-8 engines are reliable and run trouble-free. But some have experienced engine problems. This detailed survey is designed to find out more about those RX-8 engines that have had problems."
Just a thought.
<snip>
Maybe there could be a little disclaimer at the beginning of the thread? Something like "Note: Most RX-8 engines are reliable and run trouble-free. But some have experienced engine problems. This detailed survey is designed to find out more about those RX-8 engines that have had problems."
Just a thought.
Even that disclaimer would.
I won't add that disclaimer, because it is making an assumption that the claim will be backed up by the data if it could be a true sample. I simply don't know if that is true or not.
The RX-8 already has a FAR FAR worse reputation than it deserves. This survey will not impact that negatively, but might impact that positively.
For example, no where in the results do I have any intention of showing numbers of how many replacements any 1 RX-8 is likely to have. I have someone's 2 engines in the same car reflected the same as someone else's 2 engines in 2 RX-8s (yes, he has 2). Others on here, that I hope join, have had more than 1 RX-8, though not at the same time.
Even the mileage span, of saying "engines only last this long" can't really be picked out, even with a very large sample set, since there is already a general trend of 2nd or 3rd owners posting, which means that they don't know what happened before. An error rate there I will have to take into account and deal with, no way around it.
I understand the weaknesses of this. I really really do. But again, I return to: "There hasn't been anything even close to this good, and something IS better than nothing." If this shows a 90% failure rate, then all THAT data point will be is something to back up the naysayers that love bashing this wonderful car. What if this shows a failure rate equal to, or better than Ferarri, Porsche, BMW, etc...? Then we have something in data to show, that our reputation is unfairly earned.
BUT
Failure rate is the least usable stat from this survey. We can't use the information that we have a 90% failure rate, or a 5% failure rate, or 50% or what ever.
Even if we have a 50% failure rate, if we get 300+ engines reporting on, we should be able to pick out trends of what made those engines fail more easily. Whether mods, climate, oil weight usage, etc...
THAT information is what we can use as a community. And use well.
08-05-2010, 10:27 AM
#70
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And I agree the conclusions I have made are not accurate and that there are many factors that play into the reliability issues with the 8. For me, I look at the changes made to the Series II and I think the reason for the failures are obvious in the changes made to the Series II engine. Which is why I installed Mazmart oil pressure mod and the sohn adapter.
Last edited by 9krpmrx8; 08-05-2010 at 10:39 AM.
08-05-2010, 10:35 AM
#71
Failure rate is the least usable stat from this survey. We can't use the information that we have a 90% failure rate, or a 5% failure rate, or 50% or what ever.
Even if we have a 50% failure rate, if we get 300+ engines reporting on, we should be able to pick out trends of what made those engines fail more easily. Whether mods, climate, oil weight usage, etc...
THAT information is what we can use as a community. And use well.
Even if we have a 50% failure rate, if we get 300+ engines reporting on, we should be able to pick out trends of what made those engines fail more easily. Whether mods, climate, oil weight usage, etc...
THAT information is what we can use as a community. And use well.
I just used 07/01/2003.