GolfGTIforum.co.uk
Model specific boards => Golf mk7 => Topic started by: ub7rm on 26 December 2020, 16:00
-
So I've recently changed from a manual GTD hatch with nearly 90k miles to a GTD DSG Estate 2017 with 17k miles on it and have have observed the MPG difference is pretty stark. Where I would be in the higher 40's at this time of year with the old car I'm struggling to make 40 mpg on a decent run with this.
Now obviously the estate is heavier, and the DSG box is woeful, but I didn't expect things to be this bad. Is this 'normal' and if not what are the common causes of poor MPG. It doesn't seem to have had much use in its first 3 years of life and I'm wondering if this has something to do with it.
-
Looking at data for the specs you have given on Autotrader, your old car has a combined economy of 64.2 and the new car 56.5 which is a 12% difference. So if your old car was hitting 48 say, that percentage difference would have the new car at 42. So there's not much in it compared with what you are experiencing. Plus it is difficult to match year on year as there can be a few degrees difference in temperature between years at the same time. Perhaps you'll gain 2 or 3 mpg as the car gets a bit more use and loosens up but it might be that the new car is performing about right. A manual 2017 GTD estate has a combined economy of 60.2 so if economy was a priority then perhaps that was the one to go for. You may also want to check that servicing wise it is tip top as although it has only done 17k miles, it is three years old.
-
I'd expect to see my gtd hatch just scrape forty on a hour plus motorway steady cruise at this time of year. It needs to be over ten degrees to see decent fuel economy.
-
Looking at data for the specs you have given on Autotrader, your old car has a combined economy of 64.2 and the new car 56.5 which is a 12% difference. So if your old car was hitting 48 say, that percentage difference would have the new car at 42. So there's not much in it compared with what you are experiencing. Plus it is difficult to match year on year as there can be a few degrees difference in temperature between years at the same time. Perhaps you'll gain 2 or 3 mpg as the car gets a bit more use and loosens up but it might be that the new car is performing about right. A manual 2017 GTD estate has a combined economy of 60.2 so if economy was a priority then perhaps that was the one to go for. You may also want to check that servicing wise it is tip top as although it has only done 17k miles, it is three years old.
Interesting comparison - and probably does explain it. I'd actually be happy enough with 42 at this time of year. I'm just not used to seeing the avg mpg starting with a '3' most of the time.
It has had 3 services, one fairly recent so I'm fairly sure its not that. I had it in my head that DSG was more efficient than manual - I'm sure this was the sales pitch 'back in the day' but clearly not. I can see why not as well, it tends to prefer to labour in 6th than change down to 5th.
-
I'd expect to see my gtd hatch just scrape forty on a hour plus motorway steady cruise at this time of year. It needs to be over ten degrees to see decent fuel economy.
Hmm - I don't do a lot of motorway driving as such. Mostly driving on decent single carriageway A roads at 55-65 mph which has tended to give pretty good mpg for any given car. So that manual hatch would see ~47 ish this time of year and 54 ish in the summer. For the same journey now I'm barely scraping 40mpg.
-
Lots of aero tweaks... :wink:
Check to see you have the diesel full length engine bay undertray called noise insulation...
Check to see if you have the aero tray fitted to the front section of the exhaust tunnel (under gearstick)
https://www.golfmk7.com/forums/index.php?threads/how-to-retro-fit-skid-trays-aerodynamic-under-trays-stone-guards-to-a-mk7-golf.320687/#post-6659747
If not retro fit those items...
1.Then retrofit the following:-
2.Aero tray by the rear passenger side to cover the exhaust tunnel by the fuel tank.
https://www.golfmk7.com/forums/index.php?threads/how-to-retro-fit-skid-trays-aerodynamic-under-trays-stone-guards-to-a-mk7-golf.320687/#post-6659748
3.The Passat large axle cover for the multilink rear suspension
https://www.golfmk7.com/forums/index.php?threads/how-to-retro-fit-skid-trays-aerodynamic-under-trays-stone-guards-to-a-mk7-golf.320687/#post-6659749
4. Mk8 Golf aero covers for the lower rear arms
https://www.golfmk7.com/forums/index.php?threads/how-to-retro-fit-the-mk8-rear-suspension-aero-covers-or-stone-guards-to-a-mk7-golf.375175/
Whilst you are under the car you might as well fit the Audi Harmonic damper to the rear subframe...
https://www.golfmk7.com/forums/index.php?threads/how-to-retro-fit-the-rear-subframe-harmonic-damper-from-the-audi-a3-saloon-2013.369369/
:cool:
-
Is your GTD Estate a 6 speed DSG or 7 speed DSG?
I have a 16 month old A4 190 TDI Quattro Avant with DSG which is 205kg heavier than a 6 speed DSG GTD Estate.
On paper it is 53.3mpg combined. Longest run done was 190 mile round trip to Leeds with a 1/2 hour break in the middle, and got 57mpg maintaining about 75mph on the A19 and A1. On my 31mile each way commute (I only do it once a week, work from home 4 days a week) its around 50mpg in the Summer and 47mpg in the Winter. Around the doors, (journeys under 5 miles), I'm lucky to crack 40mpg. If the DPF is filling up, I'm down about 10% on those figures before a regen).
The 7th gear on the A4 only really comes into play if you're on the flat above 70mph, downhill above 60mph or Uphill about 80mph. Due to those thresholds (determined by torque I'd imagine), my A4 is more economical at 80mph (when it is almost always in 7th) than 70mph (when it spends about a quarter of its time in 7th).
Do you do many short journeys? I sometimes think that having that 7th gear could be counterintuitive to keeping the DPF clear if the engine is running cooler sat in 7th doing 1600rpm at 80 rather than 2200 rpm in 6th at 80, the car does seem to actively refen far more often than my 2013 GTD ever did.
-
I have a pretty good comparison between my old UK GTD hatch DSG (66 reg - so the old 6 speed wet box) and my current 2019 German spec Leon ST FR DSG (newer 7 speed) and the 184hp diesel with AdBlue, so very comparable to a GTD estate DSG.
My Leon returns 50mpg (over a distance of approx 30k miles) the GTD did 48 (over 50k miles).
Suspect it's all down to how you drive, I only got 30mpg during the first lockdown in spring on a run from near Munich to near Frankfurt, covered 245 miles in just 2.5 hours. At certain stretches doing nearly twice the UK speed limit for a few minutes continuously at a time...
Just week before last I did the same journey again on an eco run and managed 70mpg (in individual mode with engine/dsg in eco, steering in sport and dcc in comfort).
Doing 55-65mph on a single carriageway should return close to 50 in my experience of UK driving with a GTD hatch DSG ... but of course depends if you're mostly crusing along or chasing corners ;)
-
Is your GTD Estate a 6 speed DSG or 7 speed DSG?
I have a 16 month old A4 190 TDI Quattro Avant with DSG which is 205kg heavier than a 6 speed DSG GTD Estate.
On paper it is 53.3mpg combined. Longest run done was 190 mile round trip to Leeds with a 1/2 hour break in the middle, and got 57mpg maintaining about 75mph on the A19 and A1. On my 31mile each way commute (I only do it once a week, work from home 4 days a week) its around 50mpg in the Summer and 47mpg in the Winter. Around the doors, (journeys under 5 miles), I'm lucky to crack 40mpg. If the DPF is filling up, I'm down about 10% on those figures before a regen).
The 7th gear on the A4 only really comes into play if you're on the flat above 70mph, downhill above 60mph or Uphill about 80mph. Due to those thresholds (determined by torque I'd imagine), my A4 is more economical at 80mph (when it is almost always in 7th) than 70mph (when it spends about a quarter of its time in 7th).
Do you do many short journeys? I sometimes think that having that 7th gear could be counterintuitive to keeping the DPF clear if the engine is running cooler sat in 7th doing 1600rpm at 80 rather than 2200 rpm in 6th at 80, the car does seem to actively refen far more often than my 2013 GTD ever did.
Its the old 6 sp DSG box. Thats really good mpg for a much heavier car with additional quattro induced losses to boot. I guess the engine is an evolution of the CUNA - wonder whats different...
-
I have a pretty good comparison between my old UK GTD hatch DSG (66 reg - so the old 6 speed wet box) and my current 2019 German spec Leon ST FR DSG (newer 7 speed) and the 184hp diesel with AdBlue, so very comparable to a GTD estate DSG.
My Leon returns 50mpg (over a distance of approx 30k miles) the GTD did 48 (over 50k miles).
Suspect it's all down to how you drive, I only got 30mpg during the first lockdown in spring on a run from near Munich to near Frankfurt, covered 245 miles in just 2.5 hours. At certain stretches doing nearly twice the UK speed limit for a few minutes continuously at a time...
Just week before last I did the same journey again on an eco run and managed 70mpg (in individual mode with engine/dsg in eco, steering in sport and dcc in comfort).
Doing 55-65mph on a single carriageway should return close to 50 in my experience of UK driving with a GTD hatch DSG ... but of course depends if you're mostly crusing along or chasing corners ;)
I agree a lot is about how you drive, what kind of roads you drive on and temperature has a big influence. But the only thing thats changed is the car in the last few weeks. The official stats mostly explain the difference I'm seeing - I guess it just caught me off guard how much the difference was.
-
The aero trays mentioned by golfdave are a worthwhile retrofit.
They offer protection and improve MPG.
-
The aero trays mentioned by golfdave are a worthwhile retrofit.
They offer protection and improve MPG.
But at what cost? The expence of buying those parts would pay for a fair amount of additional diesel.
Monkeyhangers comments about DPF regens ring true with me too. I've had a 2010 Golf, 2011 Passat, 2015 Amarok, 2016 Golf, 2016 Tiguan, and can't say I've ever noticed any of them doing a regen. My 2019 Euro 6 Caravelle seems to try to do it at least twice a week. Even on a really short 5 mile round trip, I'll park up and the fans will be on and the smell of hot exhaust is wafting about. It does get good, long runs too. Even if none are planned, I'll hold it in 4th gear for a ten mile A road lorry following procession.
-
I have a pretty good comparison between my old UK GTD hatch DSG (66 reg - so the old 6 speed wet box) and my current 2019 German spec Leon ST FR DSG (newer 7 speed) and the 184hp diesel with AdBlue, so very comparable to a GTD estate DSG.
My Leon returns 50mpg (over a distance of approx 30k miles) the GTD did 48 (over 50k miles).
Suspect it's all down to how you drive, I only got 30mpg during the first lockdown in spring on a run from near Munich to near Frankfurt, covered 245 miles in just 2.5 hours. At certain stretches doing nearly twice the UK speed limit for a few minutes continuously at a time...
Just week before last I did the same journey again on an eco run and managed 70mpg (in individual mode with engine/dsg in eco, steering in sport and dcc in comfort).
Doing 55-65mph on a single carriageway should return close to 50 in my experience of UK driving with a GTD hatch DSG ... but of course depends if you're mostly crusing along or chasing corners ;)
I agree a lot is about how you drive, what kind of roads you drive on and temperature has a big influence. But the only thing thats changed is the car in the last few weeks. The official stats mostly explain the difference I'm seeing - I guess it just caught me off guard how much the difference was.
Your experience does seem to be broadly in line with published data. The only other factor may be how it’s been run in. Does it use any oil?
-
dubber36-that’s a good point,but if you intend to keep your car and you do plenty of miles,it’s a no-brainer.
If you look on golfdaves how to guide,he lists all the parts required and prices (perhaps the prices are a little out of date),also there’s a very comprehensive fitting guide for each tray-you can’t go wrong.
I got all the parts from E-Acca and whilst I can’t remember exactly what I paid,it wasn’t a fortune-about £400 springs to mind.
What’s a tank of diesel/petrol cost nowadays...£70/£80?-if you fill up using ‘v power’ like I do.
-
The aero trays mentioned by golfdave are a worthwhile retrofit.
They offer protection and improve MPG.
But at what cost? The expence of buying those parts would pay for a fair amount of additional diesel.
A few points you have missed:-
1. Those parts by improving the underbody aero also reduce the underbody wind turbulence, therefore the inside of the car is quieter, without having to rip apart the inside to add more sound deadening.
2. Some of those parts improve the stability of the car, again because they reduce the underbody turbulence.
3. Most of those parts provide protection of the underbody from stone strike etc., which is also sound deadening.
MPG on my lowly petrol 1.4lt MK7 estate is no worse than 38mpg with a heavy right foot on the twisty back roads, 42-46mpg in normal driving & 52mpg+ on long trips....But my car has 190bhp+ & 312Nm + with a Revo Stage 1-B remap (98Ron)... :grin:
People spend way more on swapping alloys "because they look better", those undertrays at least have several practical & functional benefits!!!
-
You know what, over the last couple of days the MPG has improved. No idea why. Maybe the half tank of diesel it came with was stale from sitting waiting to sell or I've blown away some cobwebs but this is more like what I would expect
(https://i.ibb.co/h2rfkyG/IMG-0796.jpg) (https://ibb.co/XF689bn)
Weird... not like its any warmer. Anyway, good to see its capable of much the same mpg I was getting from the old car.
-
You know what, over the last couple of days the MPG has improved. No idea why. Maybe the half tank of diesel it came with was stale from sitting waiting to sell or I've blown away some cobwebs but this is more like what I would expect
(https://i.ibb.co/h2rfkyG/IMG-0796.jpg) (https://ibb.co/XF689bn)
Weird... not like its any warmer. Anyway, good to see its capable of much the same mpg I was getting from the old car.
My A4 (190ps 2.0TDI) is much keener (far more responsive) with a shot of Millers in the tank to up the Cetane number if using local supermarket (usually Morissons) diesel, doesn't need it when I fill up at Costco.
-
Possibly you got more used to the DSG in addition to having better fuel?
An auto does require some change in how you drive the car. I found you cruise more than in a manual.
-
Possibly you got more used to the DSG in addition to having better fuel?
An auto does require some change in how you drive the car. I found you cruise more than in a manual.
That crossed my mind as well to be honest. I'm used to Auto's though, the 'other' car on the drive has been an auto of some sort for 7 years.
-
Possibly you got more used to the DSG in addition to having better fuel?
An auto does require some change in how you drive the car. I found you cruise more than in a manual.
Not sure whether these comments were intended for me. I flit between local supermarket fuel and Costco fuel when I'm passing (I'm not going to do a 26 mile round trip to fill up on better fuel if I'm not going to Costco anyway ). When I fill up at Costco, the car's more responsive without needing to add Millers Ecomax (detergent and Cetane enhancer). The mpg isn't appreciably better, but the puck-up is better when you use the throttle.
I am getting used to DSG - I'd rather have a manual but VAG seems to be taking that choice away for anything over 150ps. I can beat the car's own gear choices for marginally better mpg, not by a large enough margin to be bothered. When I'm driving down the A19 (about 50% of my miles these days), that 7th gear encourages me to maintain 80mph rather than 70mph, for better fuel economy (the car being in 7th much more of the time).