Crossed Flags Fan

Members of Corvette Forum arguing about a positive review of the C7??
Let's trash Mother Theresa and driving sober!!

TLC5 In CT.

My issue with C.R. is they don't publish what the actual figures with respect to the number of defects per 1,000 vehicles. For example, if their top rated vehicle has 20 defects per 1,000 and the 2nd rated vehicle has 22, the difference is insignificant on a relative basis. Secondly, I have never received a questionnaire about any of the many new vehicles that I've purchased although I am not a subscriber. Perhaps they base their ratings only on data received from. Maybe someone can comment about that.

Walt White Coupe

They only contact subscribers to CR. Here is what I received 11/4/2014 from CR:

Thank you for allowing us to contact you again. In our efforts to provide you with the most up-to-date information, we are asking subscribers who told us about their car on the 2014 Annual Questionnaire to participate in this very brief survey.
Upon conclusion of the survey, we will select 10 respondents to receive complimentary subscription extensions to ConsumerReports.org®. We will notify all winners by e-mail upon selection and awarding of extensions.

Thanks in advance for helping us with this project!


And they are very persistent with follow up emails to get us to participate.

TLC5 In CT.

Thank you for clarifying, Walt.
I.M.H.O., that brings into question just how representative the results are. I personally know quite a few vette owners and there's only one I know of that subscribes to C.R. I do admit to going to the local library to review C.Rs's comments about some items but certainly not autos.

Walt White Coupe

Maybe 2 now,

It only brings it into question because you have no idea how many people responded to the surveys. Just to start, CR has 7 million subscribers.

See: http://consumerreports.org/cro/about...arch/index.htm

Skid Row Joe

themonk

Don't they also rate electric shavers?

3 Z06ZR1

The guy doing the ratings for the electric shavers got promoted to expert C7 rating reviewer. Fully qualified!

TLC5 In CT.

Seven million is not that many considering the total number of cars on the road and the fact that not all subscribers respond to the surveys.

Walt White Coupe

Total number of cars on the road is irrelevant to this discussion. What is relevant is how many surveys from car owners were received. While CR doesn't report how many surveys were received for each model of car they did report in this latest issue the total number of car surveys that went into their current ratings. That number:

1,078,364 That's a lot of surveys.

So 1 out of 7 subscribers responded. And if an individual model does not have enough surveys to be statistically relevant, they don't rate it.

TLC5 In CT.

Everyone has their own opinion and I still believe CR's sampling for Corvettes is small relative to all owners. As such, I personally put zero value in their opinion.

Crossed Flags Fan

So, size matters...

mkaresh

The above math isn't quite right, as many people who respond respond for two cars. So probably about one out of every 10 to 11.

Total number of cars isn't relevant. Sample size is. CR's minimum sample size has long been 100 cars. This isn't based on statistical analysis, but is a nice round number. It isn't enough to report separate results by subsystem, since these can indicate differences as small as one problem per 100 cars. They often have well over 100 cars, but generally don't say how many.

One other thing not often realized: the survey is conducted in April. If a car has improved or worsened since last spring, their stats won't reflect this.

mkaresh

It's not because they have only one model year. A rating like "average" is based on a strict, fairly simple formula. Even if they have reasons to think that the rating doesn't predict future reliability--perhaps because it was hurt by a known problem that won't affect recently produced cars--they will not modify it, or even include a note to this effect.

About the dots not seeming to add up--virtually no one understands how CR calculates the dots. They last tweaked the system to try to make it make more intuitive sense in 2006. I wrote the following critique then:

http://www.truedelta.com/pieces/newdots.php

Sin City

Asking Consumer Reports to test a sports car is like asking a Amish person to review an Iphone.

BIC

I'm rather amazed by the uninformed comments disparaging Consumer Reports. I do not rely on any one source for car buying info but CR is my most trusted source. They're not perfect, but they do what nobody else does. For one, they buy all their cars anonymously from retail dealers.

CR gets NO money from auto or any other manufacturer. All the car mags/web sites have to ask for loaner cars from the manufacturers that provide all the advertising support to said mags & sites. Do you believe that the car you buy from a dealer gets the same pre-delivery inspection that the car mags get? You can bet that the manufacturers likely have special teams that get the cars ready for the mags. Likely Chevy sends Motor Trend the car they've already tested to do 0-60 in the advertised 3.7 and not the one that tests out at 4.1.

The other thing CR does that the car mags don't is gather the reliability data. True, they don't give you problems per thousand but they put all cars on a relative scale, which could be more useful. For instance the C7 is average compared to all vehicles in existence. That tells me all I need to know for me to consider the other aspects of the car. They noted the Chevy Cruze was 143% worse than average reliability. That's all I need to know not to buy one. If they didn't get enough data on a particular vehicle, they say so.

You can get different, and sometime contradictory, data from JD Powers. I don't know the relationship to the manufacturers, but the manufacturers use JD Powers in their advertising. CR doesn't allow the manufacturers to use CR's name in any advertising. Manufacturers have sued CR over test results. CR stands up and has won every court case I'm aware of. You've never seen a car mag sued by a manufacturer. They scratch each others back. I'm not complaining, I subscribe to C&D, R&T and MT. I'm just aware of their relationship with the manufacturers and possible bias so I take the reviews with a grain of salt.

I've subscribed to CR for 25 years or more. They've sent me an auto reliability survey every year. Of the many cars I've had during that period, I've found their data to exactly match the reliability experience I've had with every car. It's good to know my anecdotal experience is validated by actual statistical data--not forum BS.

As far as the road-test, CR tests all cars for months, unlike the car mags that typically test for days. The 2014 C7 Z51 coupe got a score of 92. There are only a relative small handful of cars that have ever scored that high. Rarely do such brands as Honda or Toyota break a 90. CR was just as exuberant about the C7 as was any other road test in the enthusiast sphere. CR is the only mag that mentioned the excess road noise in the coupe. I've seen a lot of forum members with that complaint, but no professional reviews (and I've read countless pro reviews). So, those that say they'll do the opposite of what CR recommends, guess you won't be owning C7s.

ONLY CR can say they don't take money from manufactures and are therefore unbiased. I'm not going to regurgitate how CR tests cars, they tell you in the mag how they quantify the tests. Don't solely depend on CR or any other single source for car buying info, but if you ignore CR, you're missing a great opportunity to be an informed buyer.

BIC

The full time auto staff of CR is testing cars every day and they have probably tested way more cars than any car mag. CR has it's own test track, no car mag has that. CR testers are not distracted writing articles about classics or racing--they test new cars--period.

If the car mags can test econo-boxes, why can't CR test sport cars?

Again, CR loves the C7. Does that mean they don't know sports cars?

silversmoke1957

Your error.

Walt White Coupe

Thank you BIC. 100%.

mkaresh

While I have issues with how CR conducts its reliability survey (or I would not have started my own), I like how they test cars. I also personally know some of the people who perform their auto testing, and they're as much car enthusiasts as the writers for the magazines. I don't know if they're able to test as many cars as the magazines, since they have to buy them all, but they're certainly able to put in more track time.

One minor caveat: they do use manufacturer-supplied vehicles for preview drives, and so do have some relationship with the OEMs, but wait until they can buy one and more thoroughly test it before releasing a full evaluation.