Golf Mk7 GT 2.0 TDi DSG bad fuel economy

[isacheema]

Hi All

my Golf GT is achieving terrible fuel economy. I mainly use the car for town driving and have a steady foot but only get 33 mpg!!In Eco the economy seems to be even worse so I keep it in normal. I’m honestly really confused as I didn’t expect it to be this bad. I have even stopped opening the panoramic roof to see if that improves the economy. I should be averaging at least 40 mpg but the fuel runs out so fast. I topped up to just over 3/4s on Sunday and in one week I have used 186 miles of fuel and only got 85 left.
Is this normal or is it a problem

id appreciate any help!

 

[Finglonga]

Town driving is never going to be great in any car as you are standing still much of the time. I would fill up and take it on a good run out of town and see what you get.

 

[isacheema]

Town driving is never going to be great in any car as you are standing still much of the time. I would fill up and take it on a good run out of town and see what you get.

Yeah I know town driving in a diesel isn’t the best but 30mpg?! Most people in this car get around 40-45 and are unhappy but that would be a godsend for me. I did take it on the motorway to Alton towers but unfortunately did not record the MPG. But I did take it on a dual carriage way with a 70 mph limit and still it only got high 30s so I am quite disappointed with it. I am also really shocked at “eco” mode as that just makes it worse for some reason

 

[JC_451]

Especially if it's cold out you'll get -horrible- gas mileage on short trips around town.

Obviously a bit different with the diesel but I wouldn't think 33 around town is that bad. If you're getting 33 on the highway then there's something to investigate.

Hit the highway this weekend and see what you get over 100 miles(round trip not per hour ) on the highway.

 

[isacheema]

Especially if it's cold out you'll get -horrible- gas mileage on short trips around town.

Obviously a bit different with the diesel but I wouldn't think 33 around town is that bad. If you're getting 33 on the highway then there's something to investigate.

Hit the highway this weekend and see what you get over 100 miles(round trip not per hour ) on the highway.

When you put it like that the town driving mpg doesn’t sound too bad but it’s very far from the urban figures VW gave. I will take it on the motorway (highway) and record the mileage, but from what I remember from my last motorway trip I topped off the tank and drove 180 miles and at the end the tank was just over half so I’m not sure if that’s bad.
Also it’s impossible to go above 75 in the UK due to them pesky speed cameras every second

 

[Finglonga]

There must be something wrong, my GTI will see 45mpg on a long motorway run. Gets over 400 miles to the tank. I would find a good inipendant garage to have a look at it.

 

[isacheema]

There must be something wrong, my GTI will see 45mpg on a long motorway run. Gets over 400 miles to the tank. I would find a good inipendant garage to have a look at it.

I don’t know if this may contribute to the problem the radar that guides the adaptive cruise control needs calibrating, as a result the ACC does not work which therefore makes the stop start not work either. Could this be the cause to the problem no plan on getting the radar sorted out soon

 

[jimlloyd40]

I don’t know if this may contribute to the problem the radar that guides the adaptive cruise control needs calibrating, as a result the ACC does not work which therefore makes the stop start not work either. Could this be the cause to the problem no plan on getting the radar sorted out soon

Stop/start not working will hurt your in town fuel mileage a little but 33 MPG isn't too bad for the diesel. Also you should calculate fuel mileage with a calculator. The in car read out isn't that accurate. Fill up the tank and then when you need fuel again fill it up the same way and calculate the real mileage.

 

[Hotsky]

Pff im happy to get 25mpg in my 1.8tsi golf

 

[relive]

Diesel has worse fuel economy on short runs than gasoline. 33MPG UK (27.5MPG US) for short trips in the city is normal.

 

[jimlloyd40]

Diesel has worse fuel economy on short runs than gasoline. 33MPG UK (27.5MPG US) for short trips in the city is normal.

Sorry but I disagree. Diesels will still do better than a gas engine.

 

[Cuzoe]

Yea... 27.5 MPG US is certainly low. My commute is 1.8 miles. I've gone full tanks only doing that drive... to work, home for lunch, back to work, home after work. Not good for any car but especially the TDI. Still got over 400 miles on the tank, somewhere between 11.5 and 12 gallons when the light comes on. That's right around 33 MPG and I wouldn't expect to see much worse. Maybe could get it just under 30 in a colder state on winter-blend with a similar commute, but if I was getting 27.5 I would be concerned.

And yes, hand calculate. Once you have a good hand calculated baseline (several tanks) you can adjust the car readout up/down to closer match your real values.

The only thing Eco does in my car (manual) is mess with steering/throttle response. In your DSG is it possible that it's keeping RPM's so low that you're spending a lot of time lugging the engine (or giving it more throttle to force a down shift)? That might be why you're seeing worse mileage in Eco. Assuming hand calculations all around.

 

[Finglonga]

I don’t know if this may contribute to the problem the radar that guides the adaptive cruise control needs calibrating, as a result the ACC does not work which therefore makes the stop start not work either. Could this be the cause to the problem no plan on getting the radar sorted out soon

Wont make any difference, Stop/Start wouldn't make one you would notice either. My S/S is disabled with no mph issues.

 

[SRGTD]

Mainly town driving may mean lots of short journeys using lower gears, with lots of stops in traffic and the engine not getting up to optimum temperature. In those conditions, fuel consumption will never be great. Also, with mainly town driving you’re likely to be getting quite a few active DPF regenerations. During an active DPF regen, extra fuel is injected into the diesel oxidation catalyst (DOC) to achieve appropriate regeneration temperatures in the DPF and this extra fuel usage will have a negative impact on fuel consumption.

Eco mode tends to dumb down the throttle response, so the natural instinct is to press the accelerator pedal harder to overcome this. In doing so, you’re probably not really saving any fuel. Better to leave it in Normal mode IMO.

How are you calculating your fuel consumption? If you’re merely using the car’s fuel gauge, you won’t be getting an accurate view of fuel consumption. If you use the car’s fuel computer, that can also be up to 10% out. To get a more accurate view of fuel consumption, IMO it’s better to calculate it manually - and not just for one tankful of fuel, but over a number of months and a number of tankfuls of fuel. Fill the tank completely, make a note of your mileage and when the tank gets down to around 1/4 full or lower, refill it completely again and then divide the distance travelled by gallons used.

Also worth checking your tyre pressures - if they’re too low, then that will also be contributing to your lower than expected fuel economy. .

 

[isacheema]

Mainly town driving may mean lots of short journeys using lower gears, with lots of stops in traffic and the engine not getting up to optimum temperature. In those conditions, fuel consumption will never be great. Also, with mainly town driving you’re likely to be getting quite a few active DPF regenerations. During an active DPF regen, extra fuel is injected into the diesel oxidation catalyst (DOC) to achieve appropriate regeneration temperatures in the DPF and this extra fuel usage will have a negative impact on fuel consumption.

Eco mode tends to dumb down the throttle response, so the natural instinct is to press the accelerator pedal harder to overcome this. In doing so, you’re probably not really saving any fuel. Better to leave it in Normal mode IMO.

How are you calculating your fuel consumption? If you’re merely using the car’s fuel gauge, you won’t be getting an accurate view of fuel consumption. If you use the car’s fuel computer, that can also be up to 10% out. To get a more accurate view of fuel consumption, IMO it’s better to calculate it manually - and not just for one tankful of fuel, but over a number of months and a number of tankfuls of fuel. Fill the tank completely, make a note of your mileage and when the tank gets down to around 1/4 full or lower, refill it completely again and then divide the distance travelled by gallons used.

Also worth checking your tyre pressures - if they’re too low, then that will also be contributing to your lower than expected fuel economy. .

Hi
Just now I got out of the car and it must’ve been doing a DPF regen as the fan was running hence the bad fuel economy I got out of that trip (27mpg). Also, this seems to be happening quite a lot is this normal? The car is now always on normal mode as I noticed the mpg kept on going down. And I use the cars trip computer (since start long term and since refuel) to help me. I’ll use your technique now