What could have caused this then?

[fasteddie]

Hi, I have had my S3 for a little over 18 Months in that time I have had it serviced twice, both times at the same Audi Dealer. After the first service I very shortly went to the Ring. After this time the fuel consumption droped (I measured this in two ways, DIS dropped from around 28-29 ave to 24-25(not including the fuel used at the ring - b4 anybody asks;-) ), however more importantly miles per tank dropped from around 300ish to 250ish). I thought may be it was the engine management "learning" to allow more fuel 'cause I drive it harder -dumb yes I know. However I have just had the thing serviced again and yet another trip to the ring and now the fuel consumption is actually better than before (returning 325miles to a tank with 25 miles range left). It's never been that good, motorway miles or not. So my instinct tells me Audi **cked up in the previous service. My question is what could they have done to have this effect, I want some opinions as I feel like I should complain. I could argue that whatever they did has cost me more than the price of the service - just want to know if they could have done something to cause this?????

 

[Timbo]

Do these periods of differing fuel consumption coincide with winter/summer? My car does ~31mpg on the DIS in winter and ~35mpg in summer, all on the same types of journeys, presumably a combination of running rich during warmup for longer in the winter and winter fuel being different.

I can't think of anything the dealer could have done to make the car worse. It's possible the ECU had exceeded an adaption parameter due to old age/dirt on sensor so it wasn't running perfectly and they reset it during your last service, but you would expect them to tell you. Is there anything unusual on the bill?

 

[fasteddie]

nothing unusual on the bill and the service interval was 1 year so no summer winter split either. I dont want to go to the dealer accusing them of something if it is unlikely something they did but I find it very strange. I've had some time to think and cant see what it could have been but the fuel consumption differential is obvious

 

[tommo-turbo]

Were they 2 different services? My last 10k service included spark plugs, but the one I'm getting tomorrow doesn't as I'm told they don't need to be done again so soon. I'm thinking that maybe if you had the plugs done last time you might be getting a cleaner, stronger spark which would increase your engines efficiency, and therefore your fuel economy. This is purely theory though! lol!

Rich

 

[Tallpaul]

Are you saying that for an entire year your fuel consumption increased?

 

[Timbo]

Have you been doing the same kinds of journeys throughout the last 18 months?

I think unless you can prove they did something wrong during the first service, the only thing you'll achieve by accusing them of anything is making yourself unwelcome there again!

Since the car seems to be OK now I think I'd let it go. I can't see how you'd get any money out of them.

 

[fasteddie]

Were they 2 different services? My last 10k service included spark plugs, but the one I'm getting tomorrow doesn't as I'm told they don't need to be done again so soon. I'm thinking that maybe if you had the plugs done last time you might be getting a cleaner, stronger spark which would increase your engines efficiency, and therefore your fuel economy. This is purely theory though! lol!

Rich

Yes they were different services, the latest one was the 60K service which is more detailed, however this doesn't exlain the drop last time

Are you saying that for an entire year your fuel consumption increased?

yes that is exactly what happened - however in my defence I had only had the car 6 months and had just taken it to the Nurburgring. I just thought I'd "open up" something??

Have you been doing the same kinds of journeys throughout the last 18 months?

yes

I think unless you can prove they did something wrong during the first service, the only thing you'll achieve by accusing them of anything is making yourself unwelcome there again!

I wouldn't go in there guns blazing I would ask them so I doubt they would be offended

Since the car seems to be OK now I think I'd let it go. I can't see how you'd get any money out of them.

I do agree and that was the purpose of asking opinion on here. I am kind of ****** off it's clear to me that the fuel consumption went up, now if it can be explained by something I did then fine. It is also fine if they say it is factualy impossible for them to caused this but I somehow doubt that this is the case.

I'm lost on this, I may just go in and ask them I didn't get the book stamped this time so I have to go back anyhow

 

[Timbo]

I wouldn't go in there guns blazing I would ask them so I doubt they would be offended

Fair enough.

If you're going back anyway there's no harm in asking if they reset any of the ECU parameters during the last service. Could point to an underlying problem? Although my experience with the dealer is that if something looks like it *might* need replacing they recommend a new one straight away!

Good luck.

 

[fingermouse]

its not just the dis reading different is it, I know mine reads miles highter after it has been reset and it takes a while for it to settle

 

[fasteddie]

its not just the dis reading different is it, I know mine reads miles highter after it has been reset and it takes a while for it to settle

No it's not the DIS, I also check mileage between fill ups

 

[larsmate]

They may have reset the ECU after your second service. I find my S3 improves all round performance including fuel economy after I pull the battery terminal off and let it do its thing with throttle body adaptation etc. The longer the distance driven between doing this (ECU reset) the better the result. This of course means you're not using as much throttle to go as fast.

 

[JonesyGT]

Whats the capacity of an S3's tank?

 

[S3tony]

62 litres