Help Please 170 avant tdi quattro fuel consumption

[kyle92]

Hi Folks,

Just bought myself a 2010 170 avant tdi quattro and the mpg seems to be pretty bad, I drove it back from wales and I struggled to get 40mpg.
Now that I have it home, on a daily basis I struggle to reach 35mpg in a mix of motorway and short city driving

I know this car will never be anywhere close to my old polo at 65mpg but I was hoping I could at least get 40-50 mpg, if I got 50 I would be over the moon but barely getting 35 means I may have to sell it as I use it as my daily runner.

I have noticed the engine seems to sit rather cool, around the 80s mark, is that normal?

I was going to have my friend map it to try and release some mpg, would that be a viable option?

Much appreciated folks,

 

[michael18mcc]

Hi Folks,

Just bought myself a 2010 170 avant tdi quattro and the mpg seems to be pretty bad, I drove it back from wales and I struggled to get 40mpg.
Now that I have it home, on a daily basis I struggle to reach 35mpg in a mix of motorway and short city driving

I know this car will never be anywhere close to my old polo at 65mpg but I was hoping I could at least get 40-50 mpg, if I got 50 I would be over the moon but barely getting 35 means I may have to sell it as I use it as my daily runner.

I have noticed the engine seems to sit rather cool, around the 80s mark, is that normal?

I was going to have my friend map it to try and release some mpg, would that be a viable option?

Much appreciated folks,

Bad Fuel Economy, Low Temp The Cause ??

I've been asking some of these questions in another thread (thanks cookstein for your help so far) but thought i should start my own thread and not hijack someone else's . It seems that my DIS is showing that I'm only getting 11.5 MPG : cookstein asked if the cars temp is at 90° so...

www.audi-sport.net

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[spartacus68]

The 2.0TDI 177bhp isn't fuel efficient. I used to get 42mpg from my old A4 B5 2.5TDI V6 and the whistle from the turbo when you floored it!

Even in summer, then I think you'll sit around 40-45mpg even with Audi Drive Select swtched to efficiency and driving like Miss Daisy. I have the same engine on my A4 Allroad. I wish I'd opted for a 3.0 litre quattro considering it can get 40-42mpg, but I wanted a manual 6-speed as I tow regularly. Quattro drive does add weight. My A4 weighs in at 1705kg.

Anyway, on the plus-points it's a great long-distance cruiser and soaks up the bumps. I've read that a remap can increase the fuel efficiency to around 50mpg, but do your research before you opt for that.

 

[kyle92]

I would be happy with mid 40's at this point but it struggles to hit 33...

It would certainly appear that my thermostat is away so I am just trying to source a manual now so I can attempt the job.

 

[spartacus68]

I think there are two thermostats on the B8 2.0TDI.

Couple of Dave Sterl videos. This is for CJCA 2.0 TDI engine.

Not same issue, but interesting all the same on CRB 2.0TDI engines on newer models that use G13 coolant.

 

[kyle92]

Mine would be the CJC engine, a handy video that.
I am still trying to source a manual.

 

[Sir Chumpalot]

If I drive like a granny I get around 45-50 mpg from my B8.5 A4 2.0 TDI Quattro. Fairly happy with that. Temps are bang in the middle.

 

[kyle92]

Getting the stat done on tuesday, I am very much like james may....dry like a granny but can go fast when I want, I know how to get the mpg from a diesel, I am hoping the stat is what is causing my issues.

 

[kyle92]

Belated update, I have had the thermostat done, 4 glowplugs changed and a forged dpf regen.
After these changes there has been no mentionable MPG difference, if anything my MPG has went down, I was getting around 450 miles to a tank, now I am getting no more than 400, it is really quite pathetic that I am averaging 31mpg...I could get better mpg in my friends A5 3l tdi!

I am starting to think that maybe it has been mapped in the past and it was done poorly? I find it ridiculous that I can get the same mpg in 3rd at 70mph than I can at 6th gear at 70mph, believe me I tested this several times....it boggles the mind!

Does anyone have any ideas???
I do now have the carista OBD2 and app as well as access to the green menu if that helps? (looking for how to actually work that green menu as well...)

 

[spartacus 68]

I remember the thread.

As the weather gets colder, then you will see a reduction in fuel efficiency, so it could be that, rather than getting worse. I used to use Forte diesel conditioner on my old V6 to get it through MOT's. Rather than simply adding it to the fuel tank, you can add it neat to the fuel filter then drive it hard. Trouble is, the fuel filter on the B8 is under the driver's side, not in the engine bay, so hardly practical. You could run the car until the fuel light comes on, then add it.

So couple of options. The car isn't running rough, which would make me think injectors, however you can get flow values checked through VCDS.

Have you checked the air intake manifolds? I wouldn't expect to see issues unless the mileage was high and you thought power was down, and the car was failing on emissions.

I suppose the obvious thing to do would be to get the car checked map wise. That said they're not going to stick it on a rolling road for free?

 

[Audiforlife]

I have a 177 audi avant not quattro though and I average around 35mpg no matter how I drive.

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[quattrogone]

Audi diesels have pretty much always been a let down especially compared to bmw oil burners, back in my b6 days I had a 1.9tdi quatty sport, only ever managed around 36/37 unless on a really long haul to the Alp's or such like...by comparison my brother had the same car but its was a fwd version and he regularly got 55+
At one point I had an A3 sportback fwd when they first came out 2.0tdi and I thought I was going to be in the realms of 50-55mpg but alas more in the early 40's....then onto a 2.5v6 tdi allroad and that was horrific lol!

Not to rub salt in but now driving a b8 dynamik quattro 2.0 petrol and consistent 33/34 with some quick driving thrown in, stuck behind stuff at 40-50mph and it will do better.

 

[quattrogone]

You need to get stuck behind some of the drivers that I have to put up with

 

[spartacus68]

Then onto a 2.5v6 tdi allroad and that was horrific lol!

I had the B5 Avant version, sport suspension, most I ever managed was 44mpg, and that's when diesel was a few pennies more than petrol. Still miss the old girl. I checked recently its MOT, so it's just done 210k and going strong.

 

[quattrogone]

The A6 allroad was a unit for sure but it still pulled like a train and to be fair for a big car it wasn't too bad on the handling front...probably having Quattro helped that lol!
I had a moment recently when I considered finding another manual one and replacing the air suspension with a lift kit, add a roof rack and a load of spotlights finished off with a winter camo wrap

 

[Diesel bob]

Try changing the o2 sensor immediately in front of the dpf. A forced dpf regeneration killed mine off and brought on engine light. Second hand eBay one fitted (£15) and I got an 5 mpg more. I reckon it had been on the way out for a while giving poor mpg but not enough to bring the light on until it failed completely.

 

[kyle92]

I remember the thread.

As the weather gets colder, then you will see a reduction in fuel efficiency, so it could be that, rather than getting worse. I used to use Forte diesel conditioner on my old V6 to get it through MOT's. Rather than simply adding it to the fuel tank, you can add it neat to the fuel filter then drive it hard. Trouble is, the fuel filter on the B8 is under the driver's side, not in the engine bay, so hardly practical. You could run the car until the fuel light comes on, then add it.

So couple of options. The car isn't running rough, which would make me think injectors, however you can get flow values checked through VCDS.

Have you checked the air intake manifolds? I wouldn't expect to see issues unless the mileage was high and you thought power was down, and the car was failing on emissions.

I suppose the obvious thing to do would be to get the car checked map wise. That said they're not going to stick it on a rolling road for free?

The winter cold/winter diesel is not a suspect in this case as when I bought it, it was getting the same mpg as I am getting now and it was 20 odd degrees then and just at the end of autumn.
I have had it plugged in and thoroughly checked, clearing previous codes that were still in memory, the glow plugs did require changing but aside that no issues at all.

I also had my local remap guy take a look at it, he pulled the current map data and sent it away to be compared with the factory original to check for alterations, he said the data was encrypted which could be a sign of a remap in the past, When I asked his opinion he said it was very 50/50 on the b8's, specially the 170, he has had some owners come back getting 45+mpg but some come back getting low 30s with no major changed except power figures.
He has been very decent and offered me a remap at £160 but I am very much split on whether I want to splash out £160 on a 50/50, if I knew it would be a positive effect I would be doing it but obviously I am in the unknown so...

 

[kyle92]

Try changing the o2 sensor immediately in front of the dpf. A forced dpf regeneration killed mine off and brought on engine light. Second hand eBay one fitted (£15) and I got an 5 mpg more. I reckon it had been on the way out for a while giving poor mpg but not enough to bring the light on until it failed completely.

I have had the issue of o2 sensors failing before, however this was on my BMW motorcycle, which also runs canbus and in turn threw up an error, if one of the sensors was out it would have been picked up in the previous plugins or on my carista, however it is a very easy one to miss that has a big impact so good shout!