Bad fuel consumption

[Teekay]

Hi, 

I have recently brought a beautiful 2010 Audi A6 Le Mans 170 diesel 2.0 tdi. The fuel consumption is averaging at between 20mpg-25mpg. I have just had it serviced so I will have to wait to see what improvements I will gain but it is still averaging the same. Audi state that I should be getting 39mpg. Can I have some advice on what I should do or why the average is so low. I am currently getting 30-35 miles per £10.

I look forward to your replies. 

Teekay

[123jaye]

I have the exact same car .I get 450 miles to a tank. Costing £77. Sometimes it only seems to average 34 mpg though. I had the 2.7 TDI saloon before and that got better fuel economy. I wish I just bought the 3.0 TDI Avant lol 

[niedzial1983]

What is your avr. jurney daily ? 

[Teekay]

Hi, 

I do the school runs on weekdays and mostly city driving. I'm averaging around 7mph.

[123jaye]

I've never found diesels to be that great for city driving.  Mines alright for mostly motorway miles. But not that great for a 2.0 TDI.

[niedzial1983]

19 hours ago, Teekay said:

Hi, 

I do the school runs on weekdays and mostly city driving. I'm averaging around 7mph.

There is your answer 🙂 diesels take a while to reach the engine temp so on city driving the mpg will be high . 

 

Mine 3.0tdi quattro does around 25mpg 

[Teekay]

Thanks for the info. 

[niedzial1983]

You need to do a longer run from time to time othervise dpf can clogg up 

[HonestTony]

I have 2.0 D and get 65MPG on a run and hi 40s round town.

are any of your brakes dragging?

[Teekay]

What would you recommend I do? I have just used stanadyne performance formula and have had a slight increase (I think). What would you recommend as I have replaced brakes and disks, cambelt change and had the big service. I don't think brakes are dragging, but how cam I check if they are? Also, what is VCDS, as I have seen this in other posts. I live in birmingham and if there is anything you can recommend with a trusted garage, please advise. 

[HonestTony]

when you say replaced brakes and discs I assume you mean pads and disks?  you will have had to press in the caliper pistons and sometimes if the piston went rusty while it was out it jams on the seals when in use- simple to test - just jack each wheel up and make sure it spins nice and freely - or if you notice some wheels get dirty faster than others - that is a sign also - and finally they will might get hotter than normal - really bad rubbing will make the whell get hot.

I had this happen on my Discovery and a new caliper fixed it

whiel you have got each wheel off the ground check for rough wheel bearings also

[Teekay]

Hi, 

I will check if the tyres move freely and come back to you. I had the disks replaced because they were worn, there was a lip on the outer edge of the disk. Can this issue be relevant to your concerns?

The mechanic that I used, worked for a vw/audi approved garage and now has set up his own garage. He said to me that the calipers were fine. The brakes do feel absolutely fine to me.

Also, Someone said to me that the engine sounds heavy who knows a bit about cars. It sounds a bit heavier since my cam belt replacement. Is there any way to find out if the engine is running at its optimum best. 

Thanks in advance for all your advice. 

[HonestTony]

I use mine on cruise alot on the speed limits and accelerate gentle 1200-2000 so I  change gear when I hit 2000rpm, and use the torque to build gently up to 2000 again, and today I only did 7 miles in heavy traffic and did 41mpg.  but I probably have lighter wheels and tires, than you, as I have 16" rims and 205 Tires!

Also I am amazed when I do a long trip 80-100 miles and I get 65MPG which is better than a brand new Skoda Suberb I had for 2 years and new Volvo V40 Cross Country 1.6D -almost.

Infact when I think about it this is the most economical medium sized car I have ever had - and I have had 35 cars so far in 29 years driving! And it is not lacking in pulling power, yes its no V12 powerhouse, but it has enough to get me round anything I need to.

BTW I about 8 years ago I had a BMW 750IL with the 5.5Litre V12 (petrol) and that would average 28MPG - so yours has got to be off!

[HonestTony]

On 10/7/2018 at 4:53 PM, niedzial1983 said:

There is your answer 🙂 diesels take a while to reach the engine temp so on city driving the mpg will be high . 

 

Mine 3.0tdi quattro does around 25mpg 

that sounds terrible my 2.7 Disco TDV6 does 25 round town and 32 on a run

[Teekay]

What do you recommend I do guys as I don't know. When the cam belt was replaced, could this have altered the engine to reduce mpg. I replaced the cam belt, done a big service and replaced pads and disks. It does also sound a but heavy, please advise guys. 

[HonestTony]

also is you air filter new or nearly new - that will help also

[Teekay]

Hi, 

I had the big service done which included the air filter. Is there any recommendations on what I need to do to check if the car is running at its optimum best. 

[niedzial1983]

Get injectors checked on a bench 

[Lee150387]

Hi there,I have a 2007 a6 c6 2.0tdi,when I reach 2000rpm it starts to judder badly and pulling away has next to no power,also I’ve noticed I’m going through fuel like there is no tomorrow and watch the miles disappear quick on the dash,anyone got any ideas?

[Steve Q]

6 hours ago, Lee150387 said:

Hi there,I have a 2007 a6 c6 2.0tdi,when I reach 2000rpm it starts to judder badly and pulling away has next to no power,also I’ve noticed I’m going through fuel like there is no tomorrow and watch the miles disappear quick on the dash,anyone got any ideas?

Have you had a diagnostic check to see if any fault codes flag up? 

If you think you've got a fuel leak get this checked at a garage asap. 

Check fuel rail and injectors.