I was wondering how much movement there is in the JD Power automotive Initial Quality Survey over longer periods. I arbitrarily decided to compare todays results with those from 10 years ago just to get a look.
The 2014 IQS is on the JD power site but I found the 2004 IQS at and old USA today article.
Here's the comparison from the 10 years :
Now you can see that there are a lot of changes there. Many brands when up or down quite a bit. Overall the median change was -4 and the averages dropped 3. So the general trend is down over the 10 years but individual brands are all over the place.
Wow, Porsche sure did turn around their quality! They went from near bottom to the top. Now you might be wondering how could that be? Surely Porsche quality wasn't bottom of the industry just 10 years ago. Well that brings us to an important thing about how the IQS works. For that I will refer you to the Car & Driver article The Trouble With J.D. Power's Initial Quality Study.
They explain that for the JD power Initial Quality Survey, the "quality" includes design features that people may or may not like. So for example if you find the navigation interface confusing then you can get a poor quality result. Thats a design deficiency but not exactly loose screws or squeaky breaks off the factory line. When I think of car quality I think of defects in manufacturing where the car fails or breaks. However the IQS survey also adds things like complaints about features. For more detail on that read the Car & Driver article, also they show how the IQS numbers varied for a few brands over several years. They also pointed out for 2011 that : "new and redesigned machines averaged 122 problems, and carry-over or lightly modified cars and trucks scored only 103 problems" So newly designed cars with new and unproven features do worse.
It would be better to look at multiple years of data and see how different car makers move up and down year to year over a longer period. That would give a better picture. Overall though I'd say the IQS should be taken with a grain of salt. Its hard to know if makers are doing poorly due to new complex features or general quality failures. I would say that if a car maker is typically at the lower quarter or typically in the upper quarter then thats a solid sign of their general quality.