Fuel consumption suddenly increases

[BL_HUK]

In recent days, for some unknown reason, fuel consumption has suddenly increased. Long-term data shows that it has gone from 40 gallons per minute (GPM) to 36 GPM, and it continues to decrease. The tire pressure is also normal, and even with colder weather, such a significant difference should not be expected.

I recently installed a backup camera, but I don't think it should have any impact. Is it possible that the wiring connections are affecting the operation of some sensors?

Has anyone experienced a sudden increase in fuel consumption and how should it be addressed?

Thank you for your sharing.

 

[Walone]

I sincerely hope it's not 36 GPM!!!

 

[BL_HUK]

I sincerely hope it's not 36 GPM!!!

Sorry, Mate.
I make a mistake, this should be MPG.
how stupid I am.

 

[Walone]

Sorry, Mate.
I make a mistake, this should be MPG.
how stupid I am.

Mistakes happen, some serious, others not, such as yours

 

[Rusty2k]

What engine do you have?

If it's a diesel it could just be the switch to winter fuel. The addition of antifreeze to the fuel mix reduces the energy content of a given quantity of fuel so more needs to be burnt to achieve the same energy output.

 

[BL_HUK]

My engine is 2.0 petrol. DSG
Every time when end my journey, I heard that my cooling fan still running 3 minutes after the engine shut down which is doesn't happen in summer.

Sent from my SM-G9810 using Tapatalk

 

[SRGTD]

My engine is 2.0 petrol. DSG
Every time when end my journey, I heard that my cooling fan still running 3 minutes after the engine shut down which is doesn't happen in summer.

Sent from my SM-G9810 using Tapatalk

Does your car have a GPF (gasoline particulate filter)? If so, the cooling fan running after you’ve switched the engine off could indicate your car was in the process of performing a GPF regeneration. Also, the regeneration process uses additional fuel in the combustion process to help burn off soot deposits in the GPF, and that could explain your increased fuel consumption. Additionally, switching the engine off before the regen has been completed will mean the car will attempt to complete it when the engine is next started, so continue to use additional fuel until until the regen process has finished (from memory, in my VW when the GPF is in the process of a regeneration, the fuel consumption typically worsens by around 30-35%).

What type(s) of journey do you typically drive? Short journeys on a cold engine will mean more frequent GPF regenerations than in a car used mainly on longer journeys when the engine’s up to normal operating temperature.

Worth having a read of the discussion thread at the link below;

2.0TSi (190) - Lumpy Running and Poor MPG

Car has done just over 1300 miles and been running great however the last few (short) journeys the engine has been really lumpy and quite hesitant, there is also some jerkiness / kangarooing despite the speed being constant. The fuel economy has also pretty much halved and I've noticed that the...

www.seatcupra.net

 

[BL_HUK]

Does your car have a GPF (gasoline particulate filter)? If so, the cooling fan running after you’ve switched the engine off could indicate your car was in the process of performing a GPF regeneration. Also, the regeneration process uses additional fuel in the combustion process to help burn off soot deposits in the GPF, and that could explain your increased fuel consumption. Additionally, switching the engine off before the regen has been completed will mean the car will attempt to complete it when the engine is next started, so continue to use additional fuel until until the regen process has finished (from memory, in my VW when the GPF is in the process of a regeneration, the fuel consumption typically worsens by around 30-35%).

What type(s) of journey do you typically drive? Short journeys on a cold engine will mean more frequent GPF regenerations than in a car used mainly on longer journeys when the engine’s up to normal operating temperature.

Worth having a read of the discussion thread at the link below;

2.0TSi (190) - Lumpy Running and Poor MPG

Car has done just over 1300 miles and been running great however the last few (short) journeys the engine has been really lumpy and quite hesitant, there is also some jerkiness / kangarooing despite the speed being constant. The fuel economy has also pretty much halved and I've noticed that the...

www.seatcupra.net

Thank you for your input and information.
My typical journeys mostly consist of 90% city driving at speeds of 30-40 miles per hour and 10% onto the motorway at 50-60 miles per hour.

I'm concerned that this type of driving might not be ideal for my 2.0-liter engine.
I'm not entirely sure if my car is equipped with a Gasoline Particulate Filter (GPF), but based on your response, I checked my owner's manual and found information about GPFs for 2.0-liter gasoline engines. It's highly likely that I have a GPF, although I haven't noticed any warning lights on the dashboard yet.
Thanks once again for your reply.

Sent from my SM-G9810 using Tapatalk

 

[SRGTD]

Thank you for your input and information.
My typical journeys mostly consist of 90% city driving at speeds of 30-40 miles per hour and 10% onto the motorway at 50-60 miles per hour.

I'm concerned that this type of driving might not be ideal for my 2.0-liter engine.
I'm not entirely sure if my car is equipped with a Gasoline Particulate Filter (GPF), but based on your response, I checked my owner's manual and found information about GPFs for 2.0-liter gasoline engines. It's highly likely that I have a GPF, although I haven't noticed any warning lights on the dashboard yet.
Thanks once again for your reply.

Sent from my SM-G9810 using Tapatalk

My VW doesn’t have a warning light for the GPF, so there’s no visual indicator on the instrument display when a regeneration is happening. Maybe Seat’s and Cupra’s are the same?

 

[BL_HUK]

My VW doesn’t have a warning light for the GPF, so there’s no visual indicator on the instrument display when a regeneration is happening. Maybe Seat’s and Cupra’s are the same?

So, the only way to determine if there's a GPF blockage issue is by observing whether the fuel consumption and the operation of the cooling fan shut down when the engine is turned off?

After reading the discussion thread you provided, I suspect I might have a GPF issue too. My daily trips usually don't exceed 30 minutes, and even though I briefly pass through the motorway for about ten minutes, the time, speed, and engine RPM don't seem sufficient for effective GPF cleaning.

I plan to follow the suggestions from the owner's manual and the advice shared by others in the thread, maintaining engine speeds between 3,500-4,000 RPM at 50 miles per hour, releasing the accelerator about 10 times or so, in the hope of resolving the sudden increase in fuel consumption issue.

 

[SRGTD]

So, the only way to determine if there's a GPF blockage issue is by observing whether the fuel consumption and the operation of the cooling fan shut down when the engine is turned off?

With my car, there are other telltale signs when a GPF regeneration is happening;
- a change in exhaust note and increased volume
- a slight sluggishness / hesitancy of the engine
- a noticeable increase in fuel consumption
- a ‘hot’ smell
- cooling fan running
- stop/start is disabled by the car.

I plan to follow the suggestions from the owner's manual and the advice shared by others in the thread, maintaining engine speeds between 3,500-4,000 RPM at 50 miles per hour, releasing the accelerator about 10 times or so, in the hope of resolving the sudden increase in fuel consumption issue.

I do this periodically.

Most of my journeys are 30 miles or longer and in just over three years of owning my car, I think there’s been two or three GPF regenerations in that time that I‘ve been aware of. Each one lasted around 1/2 hr and I was aware with the last one that it was still in progress when as I reached my destination (home). I purposely took the car out for a run the following day - even though I didn’t need to use the car that day - so the regen could finish.

 

[BL_HUK]

With my car, there are other telltale signs when a GPF regeneration is happening;
- a change in exhaust note and increased volume
- a slight sluggishness / hesitancy of the engine
- a noticeable increase in fuel consumption
- a ‘hot’ smell
- cooling fan running
- stop/start is disabled by the car.


I do this periodically.

Most of my journeys are 30 miles or longer and in just over three years of owning my car, I think there’s been two or three GPF regenerations in that time that I‘ve been aware of. Each one lasted around 1/2 hr and I was aware with the last one that it was still in progress when as I reached my destination (home). I purposely took the car out for a run the following day - even though I didn’t need to use the car that day - so the regen could finish.

Based on the information you've provided, it seems that GPF blockages are more frequent than expected, and it's puzzling that VAG doesn't display relevant warnings on the dashboard.

Furthermore, it appears that another characteristic of the 2.0 L petrol engine with 7-speed DSG is the inability to freely control engine RPM. Even when the speed reaches 70 MPH, the engine RPM remains below 2,000 RPM.
This means that the engine can't effectively clear GPF blockages while operating within the automatic transmission's range.

 

[SRGTD]

I think it’s unlikely the GPF is blocked on your car - from what you’ve described (engine fan running after switching off the engine and high fuel consumption), the car’s attempting to carry out a forced regeneration which will happen when the soot level in the GPF reaches a predetermined level. If you become aware a regeneration is in progress towards the end of your journey, if possible, IMHO it’s best to continue driving until the regeneration has finished (admittedly, it might not always be possible to do this) so your car doesn’t go into regeneration mode at the start of the next journey.

The DSG does have a tendency to change up gears early as Seat / VAG will have programmed it with emissions and economy in mind. However, you can use manual mode to override this characteristic - either by using the the steering wheel mounted gear selector paddles (if your car has these) or by moving the gear selector lever over to the left and then moving the lever backwards towards the minus symbol to select a lower gear or forwards towards the plus symbol for higher gears. Returning the selector lever back to the right puts the transmission back to full auto mode. Screenshot below is of page 252 from the Nov 2018 edition of the Leon owners manual (if your manual is a different edition, it might be a different page number);

 

[BL_HUK]

Today, I followed the instructions in the manual to increase the engine's RPM and release the throttle 6 to 7 times when driving at high speeds. This process seemed to generate enough heat to clean the GPF (Gasoline Particulate Filter), and I noticed a slight, but not very strong, odor during the procedure.

Subsequently, during my next trip, the fuel consumption returned to reasonable levels, and the cooling fan did not continue running after parking. Everything returned to normal.

I'm very grateful for @SRGTD advice and assistance.

Initially, I thought that any trip longer than 2 miles wouldn't be considered a short trip (as the manual suggests avoiding trips shorter than 2 miles). However, I still encountered situations where the GPF needed "cleaning." It could be due to the extended use of cruise control, which keeps the engine RPM constant. It appears that a bit of "aggressive" driving may also be necessary.

 

[SRGTD]

Today, I followed the instructions in the manual to increase the engine's RPM and release the throttle 6 to 7 times when driving at high speeds. This process seemed to generate enough heat to clean the GPF (Gasoline Particulate Filter), and I noticed a slight, but not very strong, odor during the procedure.

Subsequently, during my next trip, the fuel consumption returned to reasonable levels, and the cooling fan did not continue running after parking. Everything returned to normal.

I'm very grateful for @SRGTD advice and assistance.

Initially, I thought that any trip longer than 2 miles wouldn't be considered a short trip (as the manual suggests avoiding trips shorter than 2 miles). However, I still encountered situations where the GPF needed "cleaning." It could be due to the extended use of cruise control, which keeps the engine RPM constant. It appears that a bit of "aggressive" driving may also be necessary.

You’re very welcome; glad I could be of help.

Good forums are an invaluable resource for providing friendly free advice, assistance and sharing knowledge and this is a very good forum .