Hi all,

Last 3 months has seen a pretty big drop of in fuel economy. Previously 65+mph. Now 55 mph about..I know people might say that is still good BUT the car does not feel the same way to drive at all.

So losing about 80 to 100 miles per tank compared to what I used to get and doing the exact same driving.

Car has been serviced and checked twice ( different people) but nothing found. Turbo test and engine fuel response times all seem good.

The car feels slightly under powered/sluggish and you need to push harder on accelerator to maintain speeds and get up to speed.

Before car would accelerate easy and quick with little throttle use..

Previously I thought it might be tyres but sure now it is not as the car can feel good and back to normal on some runs.

You can almost tell immediately after setting off if its on a good day or not if that makes sense...

So to me there must be something a miss...Anything to do with heater/aircon or fan taking power ?

Very frustrating and just wondering if anyone out there may have had a similar issue and found out what the problem was !!!!

Thanks...

 

Colder weather, winter diesel???

DPF is getting full/blocked? Losing power is one sympton 🤔

Garage said last week DPF was fine and no build up !!!

I thought that might be the issue too or the turbo but both of those appear fine !!!

Over 3 months - surely not ? - and not been cold at all really...

Did they check engine air filter condition?

I would assume if it’s not good it would affect power 🤔

How long since it was last serviced ?

 

Could be multitude of things, clogged fuel filter, clogged DPF, poor or low oil, clogged air filter, faulty thermostat (keeping it too cold), faulty fuel pump or injector, turbo blocked or slowed (might be clogged oil feed pipe).

 

Even if serviced, some of these might not have been looked at

10 minutes ago, SurreyJohn said:

How long since it was last serviced ?

 

Could be multitude of things, clogged fuel filter, clogged DPF, poor or low oil, clogged air filter, faulty thermostat (keeping it too cold), faulty fuel pump or injector, turbo blocked or slowed (might be clogged oil feed pipe).

 

Even if serviced, some of these might not have been looked at

It was serviced before Xmas.

Had a diagnostics on the turbo and fuel injector last week - all OK...

 

@speedy9

Your op says mph but we know that should be mpg.

 

You do not say how old your car is or how many miles done.

Is it old enough that at the last service The Fix was carried out and you have new engine management and a flow device fitted.

?

Did you have this car between November 2018 & March 2019 to know what the MPG was?

Sorry - MPG ....

Car is 65 Reg. 68,000 Miles currently - I have had it for over 3 years. Never had engine malfunction light.

Never had any issues with car and nothing like htis in the other two winters.

It is not so much the drop in economy that annoys me it its just the sluggish feel.

i.e having to push accelerator harder to get up to speed and maintain it...

When it appears normal to me - car just accelerates up to speed quickly without much throttle at all.

I feel like I have to give it throttle all the time....BUT sometimes it appears and works fine bit not very often maybe 1 trip in 5 !!!

 

 

So not the Fix.

Was it at a Main Dealership and did they say there was any software update applied.

 

What is the story with the tyres and tyre pressures?

When were the tyres replaced, when were the pressures checked & have you fitted a new car mat at your side? 

 

The Winter Spec Diesel should make no difference from Oct/Nov to March as it has the same energy, but what fuel do you buy, and have you tried going for another brand?

 

PS

Are the brakes fine, serviced, no binding?

Edited 3 February, 20206 yr by Roottootemblowinootsoot

Neither of them are a main dealer - One is a very reputable VAG specialist...

Tyres are 3 months old - and correct pressures.

The tyres would not alter the feel of acceleration/power on an adhoc basis...

@speedy9

Not on an ad-hoc basis,

but they can change the indicated MPG and performance if someone goes and fits a different size like a member in the Rapid section and it changes the gearing.

So you say your car changed 3 months ago and the tyres were changed 3 months ago.

I assume worn ones for brand new ones.

http://briskoda.net/forums/topic/477007-increase-fuel-consumption

 

 

Best look in the airbox and see what the air filter looks like.

?

What fuel are you buying.  Not saying that Supermarket is bad because it is not, but changing where is a free trial.

2 hours ago, Roottootemblowinootsoot said:

@speedy9

Not on an ad-hoc basis,

but they can change the indicated MPG and performance if someone goes and fits a different size like a member in the Rapid section and it changes the gearing.

So you say your car changed 3 months ago and the tyres were changed 3 months ago.

I assume worn ones for brand new ones.

http://briskoda.net/forums/topic/477007-increase-fuel-consumption

 

 

Best look in the airbox and see what the air filter looks like.

?

What fuel are you buying.  Not saying that Supermarket is bad because it is not, but changing where is a free trial.

Car is on new tyres...

Not fuel as use a variety of different places...

Pretty sure @automass had this same issue, not sure if he ever found any reason?

The difference was that @automass did not have the car for long before getting the fuel filter changed so did not have 3 years experience of the MPG before reporting here a poor MPG.

I had fuel economy problem but not power loss. When I bought the car (91k, 16plate 1.6tdi) the mpg was normal which was 65mpg but after the fuel filter changed ( i did it myself), the MPG dropped down to as low as 50mpg. I couldnt get it fixed ever.

I did the following to fix it

Major servicing from main dealer (including cabin filter, fuel filter changing)

Wheel alignment

Shell regular diesel (always)

Had Skoda to check everything

 

But nothing helped me. my 63plate (1.6tdi bought in 62k from cargiant) used to give me 395+ for private hire driving in london by 42liters of Shell regular diesel, and 16plate was giving me 350+ with same everything

 

After the second oil change service car wasnt even starting one day. I had to call my breakdown  to take it to SKoda where they said carbon deposit in the fuel injector causing the car not starting. MPG dropped down  to 32mpg.

 

Well, Finally i had to get rid off it following by an accident. it was written off

 

Now I am owning 1.4TSI (150bhp 67plate with 27k miles). getting around 34-35mpg in Private hire driving. Not very happy with mpg but still this is DSG and Petrol. I am using any fuel regardless to compromise the MPG.

Could the problems be related to a sticky/clogged EGR valve?

Edited 4 February, 20206 yr by Gerrycan

Have they checked for a sticky caliper or made any adjustment to the hand brake?

Also have you fitted the same brand tyres than before. Older tyres with low tread will have a lower rollong resistance than new ones.  Just seems too coincidental that the issues started around the time you changed the tyres.

1 hour ago, Ecomatt said:

Have they checked for a sticky caliper or made any adjustment to the hand brake?

Also have you fitted the same brand tyres than before. Older tyres with low tread will have a lower rollong resistance than new ones.  Just seems too coincidental that the issues started

 

Yes - stick caliper was first thing they checked too.

Just all very weird...If it was tyres car would not feel different every few drives where it seems OK again...

Must be some blocked filter or valve...

I would not expect air or fuel filter flow to vary to the extent you describe.

Could be any one of the numerous sensors playing up by a small margin but enough to spoil optimum consumption. Good luck finding which one though.

Might still be useful getting a cheap obdc bluetooth connector and the VAG dpf app to monitor that function despite being cleared by the experts as their view was not under your regular operating conditions.

Another thing you could do is to compare the instant fuel display at constant speed on the flat when operating badly and normally, to see if the consumption verifies your gut feel.