Can anyone shed light on this.

I have a 2020 vrs.

18 months ago it went from 50mpg on a motorway to 31 mpg and 34 mpg urban to 20 mpg.

The first time it went to the dealership thy serviced it and did "tweeks". It came back fine.

March last year the same happened. This time they checked the oil for wrong viscosity and re programmed the dsg box and it came back fine.

A month ago the same happened. There are never any warning lights and the computer doesnt show a fault, the car runs fine.

When this issue occurs it is an instantaneous thing, not a gradual deteriation, and the car does not recover itself.

There are no warning lights illuminated.

The dealership have done an 80 miles road test and concurred that is is drinking fuel.

I only use top grade e5 and the car has only covered 50k miles.

Now I am being told that although I have an all in warranty with skoda that I may be laible for the costs, as they cannot find the cause/fault.

My question is, has anyone ever had this reoccurring issue, what was the cause, and does this sound right on behalf of skoda warranties.

Thank you.

I would fill tank to brim and then run till half full. Fill again take note of amount of fuel and work out mpg manually to check actual mpg. It may be a software issue etc and the cars displaying less mpg than it should.

Alasdair

Hi. Thanks for your prompt reply. Yes I did that. I took it on a 240 miles round trip and it used more that three quarters of a tank. It averages 34 mpg. Normally that trip nets me 50 mpg

@B3ano That was 80- miles worth of fuel wasted by them was it not? So were the spark plugs replaced at 40,000 miles, and was that after the fuel consumption was bad or before? Has the Air Filter been checked and is there a nice clean one in there? ..... Who did the Oil Services and was it 0w 20 FS IV VW508 00 / 509 00 oil showing as used. I wonder how the Dealership tech checked the viscosity of the oil used before they had to check? ? Was there a change of tyres fitted back 18 months ago? Whose E5 Super Unleaded do you use, and is that 97 or 99 octane?

Edited 15 February15 Feb by Evolution13

PS. I read your post from back in April 2025 about consumption and you not knowing about the car having a GPF. What sort of miles do you do each day. or weekly? April last year the same as this year it will be Summer Formulation petrol being sold rather than the Winter Formulation from November to March in the UK.

Edited 15 February15 Feb by Evolution13

Things I would be checking; leaking injectors, failing or intermittent O2 sensors and a blocked GPF. Also the basics; air filter and whether the car is using oil or coolant too.

I cover 150 to 200 miles a week.

All works in the car have been carried out by the same Skoda main dealer.

As for fuel it's Texaco super unleaded always.

The sparks were replaced before it went mad, and then again as a part of the 2025 issue as was the oil. So they have done about 7k each, as has the air filter.

The issue now is the computer says no faults even though there is one.

The dealer has launched a technical enquiry with Skoda to see if this is an issue.

However this is the third time my car has had this issue.

In my logical world they should by now have a fix, as they have dealt with this twice before.

So my question is, has any other member had this issue and do they have a fix.

We seem to be at the stage where if the computer can't find it then they're snookered.🤔

The Technical Enquiry is BS. They could get the car to VW UK,s technical department if there was such a thing. They could get in a proper man or woman technician with all the gear and more than basic ideas. All the best with it.

Now that's an idea. Ill follow that up. Thank you. 👍

Could it be a timing/ignition issue caused by eratic cam sensor or similar. If it was belt/chain slightly out it would be there all the time but if a sensor is sending bad signals some of the time it may explain poor mpg. I have had a failing cam sensor that doesnt always ping up a code until it went completly.

Alasdair

I just re-read the OP posting; whilst there are no warning lights, what we don't have is a proper scan of the car. Its all very well saying, there are no errors, but all cars will come with issues and dealerships (often IMHO) don't read the codes. Can you get an ODBEleven dongle onto the car, read the codes and post them up here pls?

6 hours ago, varaderoguy said:

I just re-read the OP posting; whilst there are no warning lights, what we don't have is a proper scan of the car. Its all very well saying, there are no errors, but all cars will come with issues and dealerships (often IMHO) don't read the codes. Can you get an ODBEleven dongle onto the car, read the codes and post them up here pls?

The car is with them at the moment. I'll call them tomorrow and see what can be done

As above, I'd get the car read fully. It should have been done, but then again who knows what a main dealer should do.

The next step I'd take is to run from the main stealer, and seek refuge in the warm bay of a reputable, trustworth independant VAG specialist. I would get them to find the issue, be prepared to swallow the cost, and then present Skoda UK with the problem.

Are you sure that the car is actually burning the fuel? As in, is it 100% definite that the car is using the fuel at the rate it is indicating? That would be something to check, as VAG fuel gauges are well known for being utter rubbish.

Excess fuel useage is tricky. It could be a problem relating to the car literally losing the fuel, or it could be a different problem that is causing the car to run less efficiently.

There will be a reason for this, but it might take you a little while to find it. I wouldn't hold my breath with the Technical Enquiry - among other issues raised to Skoda UK are the weird sound these cars sometimes make when reversing, the extremely poor rear caliper paint peeling, the EA888.3/4 water pump/therm housing issues, the EA888.4 engine cover issues and the discrepancies with DSG/LSD servicing (something you should look into - your DQ381 and VAQ will need servicing if they haven't already been done).

I think the independent vague technician is going to be a major option. Funny you should mention it but the paint is peeling from my rear callipers. I'm sure they won't suffer that problem at all. Lol.

Thank you for your time