2007 2.0tfsi poor mpg , what could be the cause?

[malibu200786]

Hello I'm getting really poor mpg out of my vrs I found out of the previous owner that it was quite a while ago he part ex'd the car with his boss so its been stood , my mpg has started to go up slightly in the 2 weeks I've had it and serviced it. 

These are my first 2 tanks results ....

(1st fill not full tank )

I put in £25 of shell vpower at £1.28 , it took the gauge from the top of reserve to half a tank . I reset the trip meter at the petrol station , and when the needle had got back to the top of reserve my trip said I had done 90 miles 

And the mpg display said around 18.7mpg all the way , all around town and country lanes not been on the motorway yet .

 

2nd fill..

I put in asda fuel £30 @ £1.10 , so 27litres 6 gallons 

And covered 120 miles so worked out 20mpg

Did a small motorway trip really small and mpg reading went up to 26mpg and has stayed like that for last couple of days around town .

 

 

I rarely go past 1.8x revs because I've drove diesel for years so not used to taking the engine past it , tho I have done a bit of foot down but only a little blast and still only up to about 3.5x revs .

Edited 25 June, 2017 by malibu200786

[john999boy]

You really need to do brim to brim fills to give an accurate reading. 

[Rooted]

When you have looked to see the air filter is clean, and replace if not, and you have set your tyre pressures, go into Tesco and get a tank full of Tessco Momentum 99 which @ 5 pence a litre more than 95 ron will only cost £3 a tank fill extra.

 

Then have a nice run for a while, once you find a nice spot give the car an 'Italian Tune up'.  do not lose your driving licence obviously.

A few miles of the car nicely at operating temperature, not driven like a diesel either.

Then reset the settings for Average MPG etc and see how many miles you get from running that super unleaded.  

 

Have fun.

If spark Plugs need replaced etc because you do not know when they were checked or changed do that.

[skidpan]

17 minutes ago, malibu200786 said:

I rarely go past 1.8x revs because I've drove diesel for years so not used to taking the engine past it , tho I have done a bit of foot down but only a little blast and still only up to about 3.5x revs .

 

Driving it like that will kill it. Changing up at 1800 rpm will drop the revs to uncomfortable levels. Drive the car properly using sensible revs for a petrol and you will find it nicer and probably more economical.

[willy0329]

26 minutes ago, malibu200786 said:

Hello I'm getting really poor mpg out of my vrs I found out of the previous owner that it was quite a while ago he part ex'd the car with his boss so its been stood , my mpg has started to go up slightly in the 2 weeks I've had it and serviced it. 

These are my first 2 tanks results ....

(1st fill not full tank )

I put in £25 of shell vpower at £1.28 , it took the gauge from the top of reserve to half a tank . I reset the trip meter at the petrol station , and when the needle had got back to the top of reserve my trip said I had done 90 miles 

And the mpg display said around 18.7mpg all the way , all around town and country lanes not been on the motorway yet .

 

2nd fill..

I put in asda fuel £30 @ £1.10 , so 27litres 6 gallons 

And covered 120 miles so worked out 20mpg

Did a small motorway trip really small and mpg reading went up to 26mpg and has stayed like that for last couple of days around town .

 

 

I rarely go past 1.8x revs because I've drove diesel for years so not used to taking the engine past it , tho I have done a bit of foot down but only a little blast and still only up to about 3.5x revs .

my old 20tfsi would show around 30mpg on the dash on my daily 10 mile commute, i got fed up with filling up all the time and sold it and bought a pd170 vrs and never looked back i get 50mpg on the same commute now and alot cheaper tax as well ,

yours seems a bit low from what you say , i would get the wheel alignment checked and a full service done if due and when was the fuel filter last changed ?

Avoid supermarket fuel its cheap for a reason no additives are injected into it to help clean the engine,  

Edited 25 June, 2017 by willy0329

[skidpan]

45 minutes ago, willy0329 said:

Avoid supermarket fuel its cheap for a reason no additives are injected into it to help clean the engine,  

 

All fuel sold in the UK contains all the stuff your engine needs. Its the stuff that the manufacturer specifies in the manual.

 

If they say use 98 octane its probably best to use it. if they say use 95 octane 98 will do no harm but it will do not good. It will however cost you more money.

 

I have been using supermarket fuel pretty much exclusively since the mis 80's when the supermarkets began adding fuel stations locally. Never had a single issue.

 

I had a Golf GTi which VW said required 98 Octane but would run fine on 95 Octane with a reduction of power and economy. To be honest I could tell no difference and the mpg was exactly the same on my commute using either fuel. I used to tow a trailer and race car and even then the expensive 98 octane stuff didn't make the car better. So for most of the 113,000 miles I did in the car it had a diet of 95 octane Asda and I pocketed the difference. Car was still on the road last February with just over 200,000 miles on the clock.

 

Against my better judgement when Shell introduced some special fuel about 15 years ago i decided to give it a try. Car ran OK and economy was no different but the ads said it needed at least 3 tank fulls to gain the full benefit. After 3 fill ups the car started to run like a pile of ****e. Power was down and there was a missfire. Took the plugs out and they were black. So I cleaned them and the car ran fine, strait to Asda and filled up with the 95 octane stuff. Had that car another 2 years and it never missed a beat but was always filled with 95 octane. If it did that to the plugs what did it do to the rest of the engine, so much for cleaning it. A mate unknown to me tried the same experiment and had exactly the same issues. Found out weeks later in a conversation at the pub. Not car related, his was a Vauxhall, mine was a Ford.

 

My Superb 1.4 TSi will get exactly the same fuel as the Leon 1.4 TSi before it got, supermarket 95 octane. Both run fine and both will do over 50 mpg on a holiday trip fully loaded.

[willy0329]

18 minutes ago, skidpan said:

 

All fuel sold in the UK contains all the stuff your engine needs. Its the stuff that the manufacturer specifies in the manual.

 

If they say use 98 octane its probably best to use it. if they say use 95 octane 98 will do no harm but it will do not good. It will however cost you more money.

 

I have been using supermarket fuel pretty much exclusively since the mis 80's when the supermarkets began adding fuel stations locally. Never had a single issue.

 

I had a Golf GTi which VW said required 98 Octane but would run fine on 95 Octane with a reduction of power and economy. To be honest I could tell no difference and the mpg was exactly the same on my commute using either fuel. I used to tow a trailer and race car and even then the expensive 98 octane stuff didn't make the car better. So for most of the 113,000 miles I did in the car it had a diet of 95 octane Asda and I pocketed the difference. Car was still on the road last February with just over 200,000 miles on the clock.

 

Against my better judgement when Shell introduced some special fuel about 15 years ago i decided to give it a try. Car ran OK and economy was no different but the ads said it needed at least 3 tank fulls to gain the full benefit. After 3 fill ups the car started to run like a pile of ****e. Power was down and there was a missfire. Took the plugs out and they were black. So I cleaned them and the car ran fine, strait to Asda and filled up with the 95 octane stuff. Had that car another 2 years and it never missed a beat but was always filled with 95 octane. If it did that to the plugs what did it do to the rest of the engine, so much for cleaning it. A mate unknown to me tried the same experiment and had exactly the same issues. Found out weeks later in a conversation at the pub. Not car related, his was a Vauxhall, mine was a Ford.

 

My Superb 1.4 TSi will get exactly the same fuel as the Leon 1.4 TSi before it got, supermarket 95 octane. Both run fine and both will do over 50 mpg on a holiday trip fully loaded.

octane and additives are two different things why do you think so many diesels have gunked up egrs , standard Esso petrol or diesel for example has cleaning additives supermarket fuel has no additives its just basic 95/99 petrol or  basic diesel, some times its vapour recovery petrol as well the supermarkets will take anything,

 

my point is the vrs tfsi suffers from coked valves giving poor mpg and poor performance poor quality fuel will do this ,  

[Bogwoppit]

The vRS TFSI  (BWA engine code) engine is a direct injection engine, so none of the fuel additives will clean coked up valves in this engine.

The only way to clean the valves (If they need cleaning that is) is to remove the inlet manifold and physically clean them.

[Rooted]

willyO329,

 Super market fuels is a bit misleading a term when you are talking additives and octanes.

Tesco Express filling stations can be ESSO branded.

 

Is Sainsbury's 97 ron Super Unleaded really not as good for an engine as BP's often expensive 97 ron Super Unleaded with unspecified Detergents.  (do you really want Detergents actually.)

If Gulf or Texaco 97 ron Super Unleaded actually better for Detergents / Additives over Tesco Momentum 99 with Detergents / Additives.

(Sodium as it happens to be)

Is SHELL 95 ron Unleaded a superior fuel to even Sainsbury, Morrison, ASDA, Tesco 95 ron Unleaded?

 

Nobody really has done a long term driver test like WHICH, WHAT CAR, AUTOCAR, AUTO EXPRESS to show that 10 year old cars run on fuels from Supermarket Filling stations and a bag of spanners compared to those filled up at SHELL, ESSO, BP, TEXACO, GULF etc etc.

We know that plenty Dirty Diesels are a bag of nails of ashed up DPF's where ever the fuel was bought.

 

Greenergy that Tesco part own produce Tesco Momentum 99 which has Additives and 99 octane minimum. (They also supply the 95 ron)

Grreenergy also produce and deliver much of the Esso 95 or 97 ron minimum Super unleaded in the UK to ESSO spec. (What are special about their additives?)

http://greenergy.com/uk/independent 

As to the base fuels coming into the UK or from the refineries, some of the landings, the storage and other facilities are co-owned by Greenergy & Royal Dutch Shell.

 

http://volkswagen.co.uk/need-help/owners/Fuel 

Not always about performance other than efficient running and that can be lower emissions.

If it also means smoother running but the bonus of even on occasion a little better economy the 5 pence a litre for 99 ron minimum might be worth it and nobody twists anybodies arm.

(No 98 Super Unleaded retailers in the UK, there are now several 99 Super Unleaded retailers.)

Edited 25 June, 2017 by Awayoffski

[malibu200786]

Are the catch cans any good for helping to prevent carbon build up there's quite a few videos on YouTube when you type in catch can for 2.0tfsi and they seem to catch quite a lot.

I'm going to take the inlet manifold off and give the valves a good clean even if there's not alot of build up on ? 

Why did they build direct injection if it was going to cause this many problems and reduce mpg and performance anyway . 

Any gains in design have been lost by design 

[Rooted]

How were things with the simple basics, was the air filter clean, the tyre pressures correct and have you now changed the oiland filter so the oil on is of a know quality?

[malibu200786]

Yes I changed the air filter , oil + oil filter on Monday . 

Cleaning the inlet valves by removing the manifold and using carb cleaner is not a hard job anyway so it will be worth it for me just to do it when I'm next off work in a couple of weeks .

[dilksie]

You say the car had been stood for a while. Have you checked that the brakes are not binding??? 

[malibu200786]

There not binding , the brakes work nicely and which ever one was binding would be a lot hotter than the others .

I put £35 of tesco momentum in on Monday and its been reading 24mpg since then , just been on A roads to and from work and school runs etc since then .

I put quarter bottle of redex in before topping up.

It filled up to a notch over half a tank and had gone down to a notch under half and I've done 80miles