Consumers Guide Auto Report Reliability

I have been a CR subscriber and filled-out the annual survey each year for more years/decades than I care to remember. I think one can be rely on the CR survey results for vehicles that are rated high, with few problems, because the absence of a problem requires no explanation. For vehicles that are rated low by CR due to reported problems, the CR survey results are not reliable because the CR survey does not ask for or quantify a very important variable, the cost to the car owner to repair the problem. If repair cost was included in the survey results, one could make a better judgement on the impact of the problem(s) to the car owner. Another important variable would be vehicle downtime.

The 2010 Prius rating is a good example of this defective survey methodology. It is rated "average" overall based on a single brake (non)problem for which the repair cost to car owner was $0.00 and the downtime was approximately 1 hour.

I'd have to agree with the above.

CR is great for some stuff, but not so great with other stuff. Reducing a model's overall reliability to 'average', when every other rating is exellent is kind of unfair.

REV

Great point. CR really re-defines the definition of "Average."

My memory might be wrong, but I thought CR excludes recalls. In any case CR does not purport to weight the severity or cost of repair; they are simply counting up owner complaints.

It is silly to criticize CR for doing what they transparently say they are doing.

So you are satisfied with a superficial, defective survey methodology and misleading results, as long as they are "transparent".

Absolutely. All 'report cards' are at best misleading. All you can hope for is to know what is counted, and relative weights.

'Superficial' is your own spin;
'Defective' would be if the statistics were handled wrong.

What we are talking about is a technical report on an engineered product.

A good technical report will identify the issues that are important to those the report is written for. It will distinguish between issues that are critical, important, of some benefit, or just preferences. It will provide a good analysis of performance in relation to the various issues and alternatives, and it will summarize the results clearly and unambiguously. It is also useful if it indicates how different priorities would affect the conclusions.

When a report makes assessments that have failed to address key issues (eg. cost and time), those assessments are valueless, the value of that part of the report is greatly reduced, and the credibility of the whole report is eroded.

Failing to address key issues is far more damaging than assigning and identifying different priorities from those of the reader because it is far harder for the reader to pick up. When a faulty conclusion is then pulled out into a score or a summary the report has the potential to do real harm.

CR are a good place to look for reports that less likely to be biased but it is not uncommon for them to miss or inadequately cover key issues.

As a general characterization of CR's Prius report as a whole, superficial and defective are IMHO unduly harsh. On the specific issue of the report's assessment and scoring of the brakes however, they seem like reasonable assessments. Faulty statistics is not the only way a report can be defective.

I like CR for the most part. Their methodology sure seems a hell of a lot better than JD Powers (?), which rates Porsche and other luxury brands very high because they go on number of reported problems per unit of time, not per mile driven. This vastly, insanely skews toward garage queen vehicles and is not meaningful to the average person.

A black dot may be fair for the 2010 prius brakes as long as a person knows what that means and why it got it.

CR is still the best source I'm aware of even if they do have flaws. Truedelta is also an interesting source of info and I think more people are using that. Which reminds me I'm off to put my two vehicles in finally.

For my Prius, 2010 with 19.5k miles the only issues are three of the cold-start engine shakes. But then, heck, I'd almost expect a Chrysler (I said almost) to have no issues after 20k, so it's nothing special yet. The Prius has always been a reliable car and overall the 2010 should exceed above the average vehicle, too.

I just completed the annual Consumer Reports automobile survey for my 2007 Prius.

Although I have never had a problem worth reporting, the survey asked if there were any recalls in the past year. I answered that there were two -- the pedal recall and the water pump recall.

I suspect that the same way the brake recall for the 2010 Prius apparently brought down its predicted reliability rating to "average", that next year the Gen II Prii reliability ratings will be brought down from their previously stellar heights by the past year's pedal and water pump recalls.

I also completed and sent in the 2011 annual Consumer Reports reliability survey for my 2010 Prius. Regretfully I had to check two blocks where I experienced problems, squeaks and rattles and the engine undercover. Although these are minor problems, Consumer Reports will overweight their effect on reliabilty because, under their current methodology, they equally weight all problems. I also wrote a note to Consumer Reports suggesting that they ask for downtime and cost to repair for each category and then use that data to more accurately and realistically quantify the reliability of the vehicle.

As a general guideline CR is okay, but nothing better than actual user feedback. That's what I like about PriusChat. The feedback is realtime. I've used CR for other consumer purchases and found it's recommendations to not be consistent with my actual use impressions. When I built my house, I subscribed to CR-online for appliance recommendations. I'm now regretting it. This makes be think that CR does not fully clarify their rating assumptions and parameters. They may not be as brand neutral as they say, either.