B7 saloon dynoed - 308 hp at the wheels, 320 lb ft torque

[PetrolDave]

One warm though, it does not smoke, although some have noticed that FSI's tend to smoke more than other "normal" engines.

This is a direct side effect of the direct injection of fuel into the cylinder - this tends to lead to the generation of particulates at high power and high rpms, and is not peculiar to the RS4.

[APM]

APM, did the DRC actually fail, or was it a choice to get rid beforehand? If it did fail, you must be the first one to have a failure beyond Warranty.. Did you send the letter to Audi, like the rest of us?

Marcus-rs4;yes the drc did fail(offside rear shock)i didn't send a letter as my warranty is out by 6 months plus i hadn't had any issues with
the car,maybe they could of been more helpfull,but you know dealers,even with a warranty things are a struggle,anyway drc,s gone Aps
done the lot for £1400.00.£3.600 less than audi(i don,t think they wanted to know)Audi that is.Next stop is surrey rolling road to have it dyno'd.

[Dom81]

On websites like this it seems maybe 50%+, but the vast majority of owners do not post on websites like this so that is likely an unrealistically high figure

Dave

I normally agree with your comments, but (statistically) don't understand this. Unless you believe that people intentionally join RS246 just to register a DRC problem, then you must agree that the 50% on the forum is representative of a 50% problem outside...

[PetrolDave]

I normally agree with your comments, but (statistically) don't understand this. Unless you believe that people intentionally join RS246 just to register a DRC problem, then you must agree that the 50% on the forum is representative of a 50% problem outside...

That's only true if both these are true:

1) the "population" on this website is identical to the "population" who are not active here. That definitely is not the case - we are enthusiasts, not "normal" car owners, so we are a filtered group.

2) the sample size is large enough to be representative. And that definitely is not the case either.

So any results of a poll on here cannot be take to be an accurate indication of the opinion/experience/WHY of ALL RS4 owners.

For the statistics of a sample to be an accurate representation of the whole population there must be no deliberate selection of the sample and the sample must be large enough to make the variance in the results due to small sample size low enough to not mask the real data.

Basic statistics really...

[ARSEY4]

I normally agree with your comments, but (statistically) don't understand this. Unless you believe that people intentionally join RS246 just to register a DRC problem, then you must agree that the 50% on the forum is representative of a 50% problem outside...

That's only true if both these are true:

1) the "population" on this website is identical to the "population" who are not active here. That definitely is not the case - we are enthusiasts, not "normal" car owners, so we are a filtered group.

2) the sample size is large enough to be representative. And that definitely is not the case either.

So any results of a poll on here cannot be take to be an accurate indication of the opinion/experience/WHY of ALL RS4 owners.

For the statistics of a sample to be an accurate representation of the whole population there must be no deliberate selection of the sample and the sample must be large enough to make the variance in the results due to small sample size low enough to not mask the real data.

Basic statistics really...

In that case you could quite easily select the population as being the members of rs246 rs4 owners, post up a list and decide a sample interval/sample size and ask if those people had drc problems. That would then give an accurate representation.

[SR71]

1) the "population" on this website is identical to the "population" who are not active here. That definitely is not the case - we are enthusiasts, not "normal" car owners, so we are a filtered group.

But since when is there a correlation between being an enthusiast and the DRC failing?

2) the sample size is large enough to be representative. And that definitely is not the case either.

If you are the arbiter of a representative sample size, what is a representative sample size?

Personally, I think Dom81's observations were reasonable...

Your observations about statistics may be correct, but it may also be the case that our survey is representative. The two assertions are not mutually exclusive.

Presumably Audi do actually know whether the rate at which the DRC system on the car is failing but whether or not they choose to convey that to us is anyones guess....

[PetrolDave]

Your observations about statistics may be correct, but it may also be the case that our survey is representative. The two assertions are not mutually exclusive.

Since we are a self-selected group it IS possible, but highly unlikely. We are most likely to represent the top few per cent of owners who make most (hardest?) use of their cars, are most concerned about how they perform and about how they are maintained. It's probable that a group such as us will provide early warning of any possible problems, but just because we see a 50% rate does not mean that the population of RS4 owners as a whole will see a 50% rate - that's the assertion by Dom81 that is statistically flawed.

Presumably Audi do actually know whether the rate at which the DRC system on the car is failing but whether or not they choose to convey that to us is anyones guess....

They will know it if we can persuade them to capture the data (that's the most important thing for us to do). Once they have the data I doubt that they will release it....

Remember the saying "Lies, Damn Lies, and Statistics" - we must not fall into that trap.

[APM]

Thanks Andyuk911,i wasn't aware but have put my name down.
Does this mean i'll have to wash it as its already had this months one!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[SR71]

AndyUk911,

I fancy that RR day as well....

Just to give the B5 owners a laugh and all....

[APM]

ANDYUK911 I'm in,definately have to wash it now

[Dom81]

1) the "population" on this website is identical to the "population" who are not active here. That definitely is not the case - we are enthusiasts, not "normal" car owners, so we are a filtered group.

But since when is there a correlation between being an enthusiast and the DRC failing?

2) the sample size is large enough to be representative. And that definitely is not the case either.

If you are the arbiter of a representative sample size, what is a representative sample size?

Personally, I think Dom81's observations were reasonable...

Your observations about statistics may be correct, but it may also be the case that our survey is representative. The two assertions are not mutually exclusive.

Presumably Audi do actually know whether the rate at which the DRC system on the car is failing but whether or not they choose to convey that to us is anyones guess....

Thanks - couldn't have put it better...

I agree that the whole thing is nothing more than representative - it's significant in layman's terms, but far too flawed to draw accurate statistical conclusions. Most notably there's the fact that more people are likely to register a problem than positively assert that they don't have one.

FWIW, it's statistics that paid for the car itself. They're my job, but this is nothing more than record keeping. My DRC post is specifically not a poll - it's a log as the name implies...

[Dom81]

It's probable that a group such as us will provide early warning of any possible problems, but just because we see a 50% rate does not mean that the population of RS4 owners as a whole will see a 50% rate - that's the assertion by Dom81 that is statistically flawed

Disagree. I didn't (and wouldn't) quote a %age as my post is not a poll, and has many flaws if it were used as such. I simply used the %age already mentioned, and only to take issue with your assertion that we are an unrepresentative sample. An accurate poll of RS246 members - were such a thing achievable - should closely match the wider market.

[PetrolDave]

An accurate poll of RS246 members - were such a thing achievable - should closely match the wider market.

Agreed it could be a closer match, but the issues of sample size and being a self-selected group (not necessarily representative of the normal distribution of owners) would the margin of error be small enough for even that to have results that are significant? I have my doubts.