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Poor MPG from 2.5TDi 180

Discussion in 'A4/A4 cabriolet/S4 forum(B6 chassis)' started by vrbob, Apr 22, 2010.

  1. vrbob

    vrbob Thats no Moon, Thats a space station!

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    I tried to use the search function to see if this has been covered before but it seems like the search function is mostly useless.

    So i have an app on my iPhone that calculates MPG for you i have only been using it a little while (this will be the second tank of diesel since getting it). From this i it seems the MPG i am getting is pretty poor, the app is telling me on my last tank of diesel that i got an average of 27MPG!, Now i am not expecting anything like 50MPG as i do about 50/50 town and motorway journeys but i was expecting more like 35MPG of combined driving. The car is an quattro and an auto so i know this takes away from the mpg but its got to be better than that.

    So my question is what might be the main causes for poor MPG, i have used Vagcom to check for faults which there are none, And my tyre pressures are all good and the tracking seems fine.

    Cheers
     
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  3. adamss24

    adamss24 Well-Known Member

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    I think you not far wrong as the auto gearbox and the losses on the quattro drivetrain are quite big. Is your driving style particularily heavy or do you take-it easy ? Also consider the weight of the car and the grippy wider tyres + you have 6 hungry pistons to feed ! I would fill the tank to the brim and do 100 miles of your particular drive then fill again to the brim and do the maths. The trip computer will be over-optimistic but 30Mpg average should be about right. Next time buy a manual as they will do 5-10Mpg more... These cars really shine on motorway and 40-45 Mpg is about what they will return with a steady right foot and speeds of 100+Mph.
     
  4. vrbob

    vrbob Thats no Moon, Thats a space station!

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    I do drive quite carefully and yes would of bought a manual if i could still use a clutch but my back has said no to that idea. I still think its defo doing less MPG than it should, I have had it serviced recently and the guy servicing thought that the fuel pump timing might be a little out so could that affect the MPG at all?

    Also i am not going by the DIS figures but by real world amount of miles covered to amount of diesel used and the app on my phone does the maths for me!
     
  5. nanafagis

    nanafagis Member

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    To the OP I was astonished how bad mine was when I first got it. I get an average of 31mpg mixed but mostly motorway driving on a 180 quattro, manual with 19"s. The sickening thing is I bought it as an economic compromise to an E46 M3 but by the time I pay the extra on diesel I would be hardly any worse off running the M3 with 343bhp under my right foot, getting 27mpg mixed driving and with some sideways fun when I need it!!

    I'm forever paranoid about fuel leaks as my trip always says 440-500 to a tank when i first fill up. I'm lucky to get 400 miles.


    That's where I must be going wrong, cos i've never seen above 35mpg on any of my 100-200mile motorway trecks, I must start hitting 100+ more often. I'm not taking the 19"s off, they're the reason I bought the car haha :yes:
     
  6. Leea4tdi

    Leea4tdi Member

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  7. mikeh126

    mikeh126 Member

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    Yes - same here with a 180 quattro manual - my full tank says 465 miles. But I get approx 28mpg with mixed driving ( not much motorway) - but I have had it remapped for performance. I tend to squirt it through the gears, and use the acceleration where it's safe to do so.
    If I drive really easy ( using 5th and 6th in speeds over 30mph!) I can get 35mpg - not bad for a 2.5V6 quattro with 220bhp (IMVHO, of course!)
     
  8. swarcup

    swarcup Well-Known Member

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    never checked what i am getting, not wanting to annoy anyone but you dont buy a motor like this and worry over a few quid extra at the pumps
     
  9. vrbob

    vrbob Thats no Moon, Thats a space station!

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    I would like to get about 400 miles out of a tank which i think is about 30MPG combined. Now i'm not too worried about MPG otherwise i would of stuck with the 1.9TDi like i had before but as was said earlier i was concidering an S4 but decided on the diesel for the "economy" but still wanted a bit of oomph. I have put a tuning box on the car which has made some improvement to both the performance and MPG.

    So basically there is nothing that might equate to poor MPG such as dirty injectors etc that i can check/clean/replace??
     
  10. j033y

    j033y Member

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    Reading this makes me glad I got my 190 1.8T S Line. that does roughly 31mpg combined and is a quattro too!

    i was looking at getting a 180QS tdi before getting the petrol. Mind you it does not have torque the v6 diesel does.
     
  11. vrbob

    vrbob Thats no Moon, Thats a space station!

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    I do like the torqe of the V6 it is nice :icon_thumright:
     
  12. quattrojames

    quattrojames Moderator
    Staff Member Moderator Audi A6 Audi Avant Owner Group

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    That Auto box must use some fuel then!

    My 2.5TDi manual with a DPT tuning box returns an average 35-36 mpg per tank - The DIS under reads by 3-4mpg. There are not motorways near me, so all my driving is A/B roads and I do tend to use the power. If I drive (very) cautiously into work (20 min drive) I can see 40mpg, but equally if I'm coming home late at night I'm lucky to get 25. Over a longer two hour drive at motorway speeds 36 - 38 seems typical.

    I did 2500 miles through Europe the summer before last (pre DPT box) - which was 100mph + through France, touring through the Alps and Italian Lakes and returning through Germany and I got exactly 36mpg.

    These engines do seem to really drink it if you're using the power and torque available. If you keep it to 2000 rpm and minimise use of the turbo you can easily see in excess of 40 mpg on a longer run. Apparently.
     
  13. BahnStormer77

    BahnStormer77 BahnStormer

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    yep... my experience on a 2.5TDI manual mirrors QuattroJames' experience exactly... the auto box maybe?

    you can get it to do around 25-27mpg if you try.. but if you're driving like that, you ought to be more worried about shredding tyres, your license, putting the car through something coming the other way.... the fuel fuel is a tertiary thought... normally enthusiastic driving sees just over 30mpg, legal motorway biased driving sees 40mpg, back to 30mpg once you're around the 1 ton mark... seems to average out at 35mpg per tank with a mix of types and styles of driving ... around 400-450miles before it says "zero", but that's still 10litres remaining, so you've only used 5/6ths... so it'd do nearly 500miles before you actually ran out.
     
  14. vrbob

    vrbob Thats no Moon, Thats a space station!

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    Yeah i cant see the autobox causing that much loss of MPG as if you accelerate normally eg not foot flat to the floor the gearbox doesnt let it go much above 2250rpm before it changes gear. I am gonna monitor this tank of fuel more carefully as the last 2 tanks of fuel i didnt get a good mix of motorway and normal traffic as i did more town driving plus i have been trying to sort my starting issue and some other bits so have been starting the car alot but not going anywhere.

    Think i am gona get the local independant garage i got it serviced at recently to have a look at the fuel pump timing as i wonder if that is the reason behind the poor starting every so often and my low MPG.
     
  15. swine

    swine Member

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    i'm not sure your mpg is all that bad, i'm only managing 32 with manual, so you should expect 3-5 mpg less with the auto box. i played around with a friends 1.9 passat auto and his dis showed 31 mpg on number 2 over 9000 miles he drives on a bit tho. would be interesting to see what the 1.9 quattro auto does. how's the tuning box workin out for ya.
     
  16. vrbob

    vrbob Thats no Moon, Thats a space station!

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    Tuning box is good thanks defo notice a bit more oomph plus the MPG did improve after i fitted it (just not enough :sorry:). Infact my Dad who also has a 2.5TDi 180 B6 A4 Quattro but the manual version thought it was so good he got me to find another one which i did on ebay for a similar price and his has had the same results so all good.

    Yeah not sure if i am complaining about nothing with the MPG but i would like to get 400 miles from a tank (full till the light comes on) and i would be happy. As i still have the starting issue where the car does not like to start in the afternoons sometimes and chucks out a nice cloud of white smoke i still think there must be an issue somewhere. So when i get some time and some spare cash i will get the local independant to have a looksie and see what they can find.
     
  17. swine

    swine Member

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    i know how you feel best i get is about 360-400 from full to light coming on (50 litres) but to be fair i knew what i was likely to get when i bought her coming from an a4 b5 1.9tdi
     
  18. vrbob

    vrbob Thats no Moon, Thats a space station!

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    Yeah i knew it wasnt gonna be in the 1.9 league of MPG especially being the 180bhp married with quattro and an auto box. i do like the torque of the V6 diesel and after driving the 1.9 for a few months the V6 is a much smoother quieter engine and this also being the first auto i have ever owned i have to say i am quite liking the ease of not using a clutch and gear stick.
     
  19. quattrojames

    quattrojames Moderator
    Staff Member Moderator Audi A6 Audi Avant Owner Group

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    Does your light come on with 16L to spare?
     
  20. swine

    swine Member

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    must do, i fill and reset every time and get usually between 48-52 litres back in, seems very early to come on alright, what do you get in.
     
  21. vrbob

    vrbob Thats no Moon, Thats a space station!

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    Gonna have a look with VAGcom tonight to see if my TDi timing is correct as i have (after some discussion with some of you) now found some instructions on how to do this via the TDiforum.

    These are the links that i found most useful :

    First a TDi FAQ : http://www.tdiclub.com/TDIFAQ/

    Second a nice guide with pics on how to do your TDi Timing : http://forums.tdiclub.com/showthread.php?t=240450&highlight=revisited

    Am hoping this will help the starting issues i have been getting and maybe if poss improve my MPG
     
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  23. vrbob

    vrbob Thats no Moon, Thats a space station!

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    Why does nothing ever go easy for me!

    Followed instructions for checking the timing via VAGcom go into engine then measure blocks group 000 click go then goto basic settings and there should be a TDi Timing button in the bottom right hand corner but i dont see this all i get is a button for graph and one for log.

    Any ideas? i am using the latest version of VAGcom 908 (in the instructions i have they are using version 805.1 so could that be it?
     
  24. swarcup

    swarcup Well-Known Member

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    Sorry i havn't much of a clue about how vag-com works but from reading on here i thought the pump timing was displayed as a real time graph, It should show 3 lines the top one is the upper limit and the bottom one the lower limit and your car as it is running. this line should be bang between these upper and lower limit lines. Have you tried the button for the graph while the car is running? sorry forgot to say if the timing is out then it is altered by rotating the pump clockwise and anti-clockwise to advanse and retart the timing. i hope this is of help
     
  25. vrbob

    vrbob Thats no Moon, Thats a space station!

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    Yeah i did click on the graph button and saw three lines but had no idea what these were in reference too plus i was expecting to see a drop down box for my engine but couldnt find that either.
     
  26. swarcup

    swarcup Well-Known Member

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    sounds like your almost there. try giving a pm to adamss24 hes the guy who knows these engines and the vag-com inside out.
     
  27. vrbob

    vrbob Thats no Moon, Thats a space station!

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    Gonna leave it now as am going out tonight so will let the replies pour in explaining why i cant do this and have another go 2moro.

    Will drop Adamss24 a PM 2moro if i am stilling hitting my head against the dashboard trying to work out why i cant do this ;)
     
  28. adamss24

    adamss24 Well-Known Member

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    Try to check the tdi timing in basic settings block number 4 then the engine should rev to 1100rpm then you will have the tdi button on the right hand side of the screen. Press that then select the v6 tdi at the bottom of the drop down box. Make shure the engine is hot at 80 degrees Celsius...
     
  29. vrbob

    vrbob Thats no Moon, Thats a space station!

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    Cheers adamss24,

    Was just heading out when i thought i would check to see if anyone had replied, Will give what you said a whirl 2moro and see what happens.
     

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