2.0 TDI 170 Fuel Consumption

[marcus]

I wouldnt mind betting the DPF filter has something to do with bad fuel consumption. When i had the car from new fuel consumption was pretty good and over the last 18 months has gradualy got worse. The reason for the early service was a blocked DPF filter which made the car undrivable, and now on top of the service not only does she run better but fuel consumption has increased far more than one might expect from just a service.
Has any one else got any thoughts on the DPF filter and is it really necessary!!!!

[John140]

I think they meant the design of the EGR valve, which is the valve that opens and closed to allow hot exhaust gases into the air intake (helps cut NOX emissions).

[John140]

I understand that there are 2 engineering approaches to the fittment of a DPF filter. Option 1 is to use the injection of a small amount of special chemical (known to Peugeot Citroen people as Eolys fluid) to keep the DPF clean. The second option which VaG adopted, is to go for an ECU controlled cleaning cycle for the DPF by altering the fuelling to periodically raise the EGT to the point where it burns the DPF clean. I think this is why people experience sporadic poor consumption, because they may be driving on a day that the ECU decides to do the 'clean cycle'.

[JohnH]

I was looking for this thread as I posted regarding my disappointment in the fuel consumption of my 170 TDi before.

Since its service it has been transformed, it's much more tractable - pulling smoothly from a little over 1000rpm - which makes joining roundabouts a lot less tiresome.

The biggest surprise is the fuel economy, from struggling to better 40mpg (however I drove) - I now regularly see 50mpg on a motorway run at the legal limit and actually managed an indicated 60mpg on a 150mile run at 60mph (traffic was very heavy so I just tucked in to the slow lane with the lorries and set the cruise control).

So overall I'm pleased.... they've also replaced the steering rack and clutch and so the car doesn't 'moo' or judder any more - drastic but effective I guess !

[RicardoA4Sline]

I have owned my 170 avant since July 07 and some 23K miles. Mine has improved to 42mpg, but my usage has gone to more motorways (now up to 4K per month!) and these journeys are about 47mpg cruising at normal speeds. However town driving is barely above 35mpg.

I do find this is bad considering how good my old Golf 130 was with over 50mpg. Fortunately for me its a company lease car and fuel card supplied, I can understand posters comments about BMW320d models as a collegue has one and it does about 600+ miles on a tank....which I can but dream of.

Also mine is very laggy compared to my previous diesels Golf and Volvo S40 (about 130bhp each) and needs revving to make it shift, it has had a software upgrade at 1st service a month ago but doesnt seem any different ( confirmed by the dealer)

Would love to see what difference a tuning programme would do but my company wouldnt be best impressed.

Still love the car though, apart from the wooden steering feel and noisy climate control

[bogey888]

Just dropped car off to Audi cos of 'lumpy' engine, poor fuel economy, no power etc, spoke to service department and there is a 'recall' on the engine, update on ecu, so wish me luck on the outcome......

[mcmahonleon]

Update on the fuel consumption issue I raised at the end of last year - after constant moaning to my local dealer, they finally relented & reluctantly took the car in for a thorough inspection. It transpired that the ECU had been incorrectly programmed at the factory - they reprogrammed & the fuel consumption rocketed to mid-late 40's. Problem solved but unfortunately no compensation for all the cash I'd spanked on wasted fuel.

Outside of the fuel consumption issue, I've always been very disappointed by the huge turbo lag when pulling away - nothing, nothing then everything! This is sometimes dangerous at roundabouts etc & has shredded through several sets of tyres. Again, I moaned to the dealer & was told this was a characteristic of the engine & to deal with it. Last month, I experienced jerky throttle response at motorway speeds & took the car to the dealer. They investigated & found that my injectors were blocked & replaced under warranty. This cured the throttle response problem, but more importantly has almost completely removed the excessive turbo lag at pull away speeds! I suspect the injectors have been a problem from word go.

All in all a much better car, but it has taken me 45K miles into ownership to get satisfaction. I have however learned two very important lessons in the process though - keep moaning & never buy another Audi (back to BMW for me).

Hope this helps as I'm sure I'm not the only one that's ended-up with a 'friday afternoon' A4!

Note - I've taken all the repair reports on face value & do not know if they've carried out any software updates/ retrofits that have helped cure the fuel & lag problems.

[sefton1]

37mpg on average is wonderful compared with 23mpg of my old 3ltr beast so im well chuffed

[robbielees]

I think this is awful fuel economy. I traded a 2.0 TFSI TT in Jul for an S line 170 avant, hoping for a bit of practicality (yes) and good fuel economy (no!) To be frank, driving the TT for fun returned between 30 and 33 mpg, driving the avant carefully returns 33-37, doen't even offset the increased cost in diesel over unleaded. I'm fuming as my dealer talked me into the 170 in defference to the TT, and said he drove one hard getting 40mpg plus. Reading these posts I'd say that was a complete fabrication.

I note that no one is really getting close to the published figures (not on but close) - it seems Audi aren't providing what they're selling, do we have any come back??

[Giles H]

Been reading the posts and I just had to say something.....

I run a 2006 140ps TDi which I've had from new with 70,000m on the clock. I do a lot of motorway miles but also live out in the stix....so I get to play a little every now and then ....I generally get 650 miles out of a tank of standard tesco stuff....but on one trip up north, i wasn't in a hurry....steady 60mph...and the DIS eventually told me after a few miles that i had 1200 miles left in the tank!!!! So.....take it slow and steady and they wont cost you a penny! lol

However.....

....who wants to do 60mph!?

Oh....and I had it on a rolling road near me (a calibrated one)....and she was kicking out 153bhp after 20,000m! And no...I haven't touched anything on it! Can't be bad!! lol