Audi A3 Sportback - Low diesel MPG - is it me or the car?

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Mon 28 Feb 2011 21:53
Audi A3 Sportback - Low diesel MPG - is it me or the car? - PetrosPetros

Hello,

I've just bought a used Audi A3 Sportback 1.9 TDI, because I'd read tons and tons of websites saying people got real world mileage of 50+ MPG.

So, with bated breath (erm) I did the math - 481 miles off 61 litres works out at about 35 MPG. Needless to say I am pretty disappointed.

There seem to be lots of MPG comparisons, but not many offering technical solutions to things which might be wrong with the car.

Should I be going into a garage and asking them if there's something wrong with my car? Its under warranty so I want to rule out any technical probs in the next 2 months.

On my previous car - a 58 plate 1.8 petrol Honda civic , I used to get 38MPG regularly, last month - up to 44MPG in the summer time. So without majorly changing my driving style, is it unreasonable to expect the MPG to be better on the Audi? Or do I have to 'relearn' to drive a diesel? I'm worried I've gone backwards in terms of fuel economy...

I've read that on the internet that the wobbling at idle when its warm might be the injectors. Is there anything else I should look out for? Or am I better off going straight to the garage with an open mind?

Thanks for any ideas in advance!

Pete

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Mon 28 Feb 2011 22:01
Audi A3 Sportback - Low diesel MPG - is it me or the car? - Peter.N.

Hi Pete

If you are getting 38-42 from a petrol you style of driving shold be giving you 50-60 mpg from a diesel. Driving a diesel is different though, you need to keep the revs down by changing up early, diesels are most efficient at about where they develop their maximum torque which is usually about 1750-2250 rpm, if you drive it like a petrol car ir won't give good consumtion, you don't normally need to change down to overtake, just put your foot down.

Having said that you would have to drive it pretty hard to get it that low, check the real world consumption by filling the tank to the brim and then again when it needs fueling and work it out exactly - or is that what you have been doing?

Peter

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Mon 28 Feb 2011 22:27
Audi A3 Sportback - Low diesel MPG - is it me or the car? - PetrosPetros

Hi Peter :)

Yes, I filled up, did 480 miles, then filled up again to get the MPG. About 50% of that was steady dual carriageway driving.

I'm not going much over 2500 rpm - although when I'm cruising at 80 its doing about 2,800 rpm. Sometimes I do wish it would get off the ground a bit faster. Something feels not right, as I thought I'd get more oomph out of the turbo when I floor it.

So if I'm getting almost half the MPG I should expect, then I guess I need to make a trip to a mechanic... Could it be almost anything, or are there some likely candidate problems that would cause this? I don't know much about how diesels work internally... Its an '07 plate A3, but its got 120,000 miles on the clock so its abnormal mileage for a car that age - but I thought they ran forever...

Cheers

Pete

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Tue 1 Mar 2011 09:55
Audi A3 Sportback - Low diesel MPG - is it me or the car? - Peter.N.

I'm fairly new to common rail diesels although I have been running IDIs for 50 years or more but I have recently bought a Peugeot 406 Hdi which has covered 190,000 miles and is averaging nearly 50 mpg.

They are very much more complicated than the old ones, MAF sensors and injectors can be responsible for poor fuel consumption I believe, I think a trip to a diesel specialist is probably going to be your answer.

Some of the modern diesels don't seem to be as durable as the old ones although the early Peugeot / Citroen ones are looking good, I have seen several 406's with over 300,000 miles on the clock, that was what influenced my choice.

Peter

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Tue 1 Mar 2011 17:27
Audi A3 Sportback - Low diesel MPG - is it me or the car? - craig-pd130

Is it a 105bhp or a 130bhp variant? Either way you should be getting more MPG. Injectors could be a little worn, the PD injectors can get a little tired at 120K+ of mileages.

Could also be the Mass Air Flow (MAF) sensor being tired, another possibility is the coolant temp sensor. What does the water temp gauge show?

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Tue 1 Mar 2011 19:39
Audi A3 Sportback - Low diesel MPG - is it me or the car? - PetrosPetros

This is all really useful - I now have a list of things to ask the garage man which otherwise I never would have dreamt of as a diesel newb...

Its the 105 variant - are they vastly different engines or is it just a case of tuning? Which I might consider after fixing whatever the current issue turns out to be.

The temp guage on the dash climbs to the middle and stays there so no evidence of any cooling problems. But in this weather its probably not testing the cooling system to its hardest!

I've got it booked into the local garage for a check, so hopefully they'll find something and it won't be too expensive.

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Tue 1 Mar 2011 19:55
Audi A3 Sportback - Low diesel MPG - is it me or the car? - gordonbennet

My son had a Seat Toledo with the 110hp version of the 1.9pd.

Driven hard, which is his only driving style it returned never less than 45 mpg.

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Tue 1 Mar 2011 20:31
Audi A3 Sportback - Low diesel MPG - is it me or the car? - PetrosPetros

So, I think the conclusion is its the car, not me - which is reassuring! I am officially not going mad.

Will a "diesel specialist" do things that my local garage won't be able to? Can anyone recommend one in the Exeter area?

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Mon 11 Apr 2011 12:06
Audi A3 Sportback - Low diesel MPG - is it me or the car? - Chuckie888

110 HP version was not a PD

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Tue 1 Mar 2011 20:47
Audi A3 Sportback - Low diesel MPG - is it me or the car? - Roly93

I think in this car with this engine you would have to actively try to not get at least 45MPg on almost any sort of journey.

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Tue 1 Mar 2011 21:14
Audi A3 Sportback - Low diesel MPG - is it me or the car? - Peter.N.

I can reccomend a diesel specialist in Honiton, only I can't remember what they are called, they are on the industrial estate at the Exeter end, as you are coming out onto the A30, you can see it on the right as you are coming in from Exeter.

I haven't personally had anything done by them but they were very helpful when I phoned them about a problem, I also sent a friend down there with a leaky pump on a BMW which they had been quoted several hundred pounds for and they did it for less than a hundred.

Certainly worth a try.

Peter

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Tue 1 Mar 2011 21:30
Audi A3 Sportback - Low diesel MPG - is it me or the car? - PetrosPetros

Was it Cowick Fuel Injection Services?

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Tue 1 Mar 2011 21:36
Audi A3 Sportback - Low diesel MPG - is it me or the car? - Peter.N.
No, this one. Diesel Injection Services (Devon) Ltd

Reme Drive, Heathpark Industrial Estate, Honiton, Devon EX14 1SE

  • Tel: 01404 47919

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Wed 2 Mar 2011 10:02
Audi A3 Sportback - Low diesel MPG - is it me or the car? - dieselnut

Whoever you take it to needs to have the diagnostics to read live date like VAGCOM or VCDS.

You don't mention any EML light showing, so will probably be a sensor sending back wrong info.

Problem is often a faulty MAF when there is no EML.

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Sat 5 Mar 2011 18:58
Audi A3 Sportback - Low diesel MPG - is it me or the car? - PetrosPetros

In the end I started off by taking it to a local garage and asking them their opinion...a quick look under the bonnet and we found it needed an oil change plus a new air filter and fuel filter.

After doing that, it seemed to run much better. Obviously time will tell once I've re-calculated my MPG - but for the time being it seems the lesson is that before spending big bucks on MAF sensors and injectors etc, the first port of call is a basic service!

Fingers crossed this will have worked...

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Sat 9 Apr 2011 17:25
Audi A3 Sportback - Low diesel MPG - is it me or the car? - Xanthos

hello,

i have just bought an Audi A3 2.0 lt diesel and it seems that i have a big disapointment fuel consuption too even though i allready changed all the filters.I have maximum 33mpg town mileage.did you manage fuel consumption issue?

by the way are you from Greece or Cyprus? cause you are name is greek

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