a6 2.5tdi quattro tiptronic 20mpg??

[partric]

I have a 54 plate A6 Avantv6 180bhp tiptronic final edition with 150,000 miles on clock. I'm only getting 20mpg around town and with heavy right foot this is about 14. The best i can achieve is 22 driving so steady your grandma overtakes you. I get about 30 on a run about 70-80mph on motorway. Any suggestion whats wrong. No fault codes on Engine or Gearbox at a Audi Specialist Garage but only had car couple of months. Drives brilliant, no blips and Power great all way through.

The car is 3000 from next due service.

[iwaters]

I've got a petrol V6, 170Bhp and I get about the same figures as you so you have a problem.

It is tempting to say there is a problem with the MAF but with no drop in performance or any fault codes this seems unlikely.

Also is this based on what the computer tells you or are you calclulating it manaully? It could be the computer that is faulty.

Have you checked for leaks?

[partric]

HI and thanks,

The fuel consumption is from brim to refil to brim and fuel computer proved to be within 5% of my workings everytime. First garage thought it was gearbox as it stays in low gears when driving round town slow when could do with changing up. Gearbox specialist which is known for being the best near me checked it all out and said perfect and test drove it stating drives one of the best ones he's drove for mileage!!! He also plugged in so no fault codes at 2 garages.

[iwaters]

Has it always been like that since you woned it or has it started with the cold weather recently? Cars will use more fuel in cold weather.

Are you getting any excesive smoke? There could be a fault with one of the injectors dumping to much diesel into the cylinder, or leaking from the seals around it. Did either garage check the injectors?

[The Mk3 man]

If you've never had the car serviced yourself and don't have a fully itemised bill for the service history then I would be inclined to get the fuel and air filters changed ASAP.

[partric]

Ive only had the car couple of months so no service myself yet. The service history isnt itemised so will get filters changed thanks"the mk3man"

iwaters no injectors were checked but no excessive smoke at all

[snapdragon]

I had this problem until I did a scheduled change of timing belts, waterpump and thermostat. I think the camshafts and/or injection timing was off optimum, as mpg has been greatly improved since February 2010 when it was done.

[kid-jensen]

If your gearbox is changing up late, that will have a significant impact on your fuel consumption...and I don't mean improve it.

Might be worth disabling the "driving style learning feature" of the tiptronic. I's been know to play up and settle on a more sporty mode all the time... Disabling it should make it change up early on light throttle openings, without affecting things when you mash it.

Do a search here, it's all spelt out.

You'll need a VAG-COM to interrogate the ECU.

[partric]

Hi and Thanks Kid-Jensen,

I've heard about "Driving style learning feature" before and have done a search but cant find it in on this site or your posts.

[kid-jensen]

With greatest thanks to "Nora2004", here's the instructions

you will ned Vag-Com to do any changes, so assuming you have that;

Connect to the car with the engine off, go to Trans group, from here you can see a recode button, hit that.

A new little box will appear which will let you chnage the number which is in there, std should be something like 0001.

Simply change this to 0031 and press the do it button, exit all the menus, start the car and enjoy!

This switches off the DSP, so no more learning your style and confusing itself, it wshould now enable you tu use the shift buttons on the steering wheel whislt in D mode!

And in TIP mode it will hold 1st gear for as long as you like and not try to change up as soon as you let off the throttle!

And of course it chnages the shift patterns in normal D mode, something which i love!