Consumes too much diesel

[Tariq Khan]

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

 

[smog c6]

What sort of driving, it’s about right for stop start cold engine. If you live in city and do less than 10 miles and it’s all traffic you will get 25 mpg. Motorway should be high 40’s sticking to 70mph. Post average speed up.

 

[Tariq Khan]

Hi Smog c6,

Thank you for your reply. My average speed is about 6mph and my c6 is not a stop start. It is a audi a6 le mans 170 2010 2.0 tdi. I am averaging at 21.7mpg.

 

[smog c6]

Yeah, 20-25 seems about right with an average of 6mph. I meant “Stop Start” traffic not engine. Good idea to change fuel filter as I’ve seen mpg go up on mine by 3-4mpg after changing it.

What did you drive before this.

Problem with an a6 is it’s a heavy car. it’s like driving a golf with an extra 400kg. If you weigh them they are usually around 1750-1900kg.

 

[Tariq Khan]

Hi Smog c6,
I had a 1.4 hyundai i30, so yes I was expecting a difference. I just thought that because it states a combined 39mpg on my model that there might be something wrong. I brought this beauty with no service book, I have had a big service and changed all pads and rear discs. Would you advise on a cam belt change, keeping in mind that the car runs smoothly. Also, I have been quoted from the mechanic for £480 this is genuine parts fitted (this mechanic is not approved as he has opened his own garage but was working for a approved dealership for some years prior to this).

Look forward to your reply.

 

[UmarA6]

Hi Tariq,
I have the A6 3.0 TDI and one of the things i learnt is that these cars take a hammering in town, i have had mine for 9 months now and if the car has warmed up you can get between 25 to 30 mpg depending on your driving style but if the car is cold or your stuck in a lot of traffic i wouldn't be surprised if you get less than 20mpg, when i start mine from cold in town, i see as low as 6 mpg but these vehicles strive on the motorway which i do alot of driving on and you can get good some good mpg's at decent speeds, like its not uncommon to drive at 80 mph and still be achieving mid 40's, which is pretty decent for big barge like this and with a 3 litre engine

 

[Tariq Khan]

Hi UmarA6,

I have just learnt to accept the low mpg. I love this car, it drives beautifully. I do the school run everyday, and I basically start the car in the morning and drive off. I am currently getting 175 miles per £50, this is about the same if I use cheap supermarket diesel or a premium diesel regardless of what the computer is showing when I fuel up. Do you reckon if I let the car warm up before I drive off, will this improve mpg. Also, on average how long does it take a cold car warm up. Mine is a 2.0tdi lemans 170.

 

[UmarA6]

i would personally say to start it and drive off but drive in low revs, so don't rev it hard till its warmed up, i normally start mine and and head towards the motorway which is about 3 miles from my house and by the time i get their its already warmed up but i would be doing short runs of 40 or 50mph till i get to the motorway, i found that the car has to be driven at higher than 30mph to get it warm quick but you cant really do that in the city unfortunatly. have you tried using Shell V power Diesel, as you might have gunk in your fuel lines which is making your car drink more, personally i use vpower diesel once a month but give it 2 tanks of it so the car gets use to it properties, it might be 9p a litre more expensive but you get better mpg of that and it cleans your internals of your engine. The A6's are Beautiful cars and you will not want to get rid of it, i have looked at so many other cars whilst owning this and even the newest C8 A6 doesnt have the same experience as the C6 does, their nice and comfy when you want it and can be very sporty when you want it to be aswell

 

[RS_Dan]

Probably about right if you are stuck in heavy traffic.

Do you ever get chance for a good motorway blast for oil to get up to temp and a DPF regen

 

[RS_Dan]

Umar, when you say 3 miles to get warmed up are you talking about coolant?

My Tiguan R used to take about 15+ miles for the oil to get up to temp

 

[UmarA6]

i am talking about coolant getting warmed up after about 3 miles, once my coolant has warmed up the engine starts getting alot better mpg

 

[UmarA6]

oil takes about 15 mins to get fully warmed up

 

[Tariq Khan]

I have been reading other threads in which some people mention the injectors not being clean. Is there any additional additive formulas in the market which will help in cleaning the injectors. Or do you reckon that due to me doing majority of city driving with traffic, that my mpg is about right. I do get the odd motorway blast but 90% is city driving.

 

[UmarA6]

you can use shell vpower diesel which would do that but for majority of city driving, your not really going to get that much better mpg

 

[Pyeman]

Hi Smog c6,
I had a 1.4 hyundai i30, so yes I was expecting a difference. I just thought that because it states a combined 39mpg on my model that there might be something wrong. I brought this beauty with no service book, I have had a big service and changed all pads and rear discs. Would you advise on a cam belt change, keeping in mind that the car runs smoothly. Also, I have been quoted from the mechanic for £480 this is genuine parts fitted (this mechanic is not approved as he has opened his own garage but was working for a approved dealership for some years prior to this).

Look forward to your reply.

OMG.

You clearly didn't do enough researching before buying.

Audi state combined mpg over a certain distance and conditions But not with an average speed of 6mph, so you clearly bought the wrong car!

The A6 weight is nearer 2 tonnes not half like a i30. The A6 is twice its size if not bigger.

You should have bought a A3 or a Golf if mpg is your thing.

However, if there was a fault to cause poor mpg, scanning and looging with VCDS or similair will show data and a fault code for this.

 

[B5NUT]

If my average speed was 6mph on my commute to work I would either walk or buy a bike. If you are doing that sort of trip every day then a very small petrol engine car would be far better, it's not good for a diesel to be doing that sort of speed, due to the time it take to get the engine up to temperature and your DPF will get clogged up in no time.

However as far as your MPG goes would say that is good, but I would expect it to drop even further with the cold weather, and for it to take even longer to get the engine up to temperature.

 

[Tariq Khan]

Hi guys,

Thank you for your input. I don't actually think I average that low of a speed but that is what the computer states. I just flagged this up because my average mpg was so different from what I have read so I was basically trying to work out if there is something wrong. Can I presume that premium diesels should help clean the injectors but would you also advise on putting additives like Millers in?

Can you also advise me on fault finding to see if I am getting the correct mpg.

 

[smog c6]

If you want the best car for mpg buy a golf 1.9 tdi with no DPF, 105 bhp version. Those things will do 40 mpg in town driving even from cold. There are newer engines eg 1.6 tdi but if the purpose is to save money then buying the older 1.9tdi is better. Almost 0 depreciation and it’s a simple engine cheap repairs pretty much every fault possible with them is on google.

If you want a luxury car for town driving buy a petrol it will do the same mpg as a diesel in stop start driving. Even a 3.2 fsi gets similar mpg to a 3.0 tdi in city driving conditions.

 

[Mr DJ MOORE]

I have the issue where my joirney to work used to be pretty much like highway driving, but now there is so much traffic on the roads I spends ages sitting in queues.
My car seems to drink more fuel than I'd like in traffic, I suspect I might need to look at injetors or DPF next. Perhaps even renewing the timing chains if I'm feeling adventurous although I'll need some new tools and another car for a few weeks to allow me to take my time.

 

[Tariq Khan]

I have had the cam replaced, full service, pads and discs replaced. I love the car and will not sell it for 2 years but it does feel heavy.