40mpg realistic for a T6.1 150 DSG Ocean?

[bob_summers]

So now it's on the way, I was wondering what difference I'll see in economy from my T5 1.9tdi manual.

Over a long journey (don't use the van midweek) I get 40-42mpg - I'm very lightfooted, setting cruise control just a few km/h faster than the lorries.

Now it's on its way, I was wondering how it'll stack up against my old manual T5 1.9tdi in terms of economy. Interested in motorway economey really, as i don't use the van midweek etc.
Progress would suggest better, but the Ocean is heavier and automatic...


Read some economy threads but you all seem to boot it more than me!

 

[subthree]

I have a 150 DSG 6.1 Ocean. Now covered just shy of 6,000 miles. Not a daily driver so when we go out it is normally on a longer run. I travel at just over 70mph, when the limit allows. Without ACC (adaptive cruise control) you will get a higher mpg. I have seen high 30s but not low 40s. However if you are travelling slightly quicker than the HGVs then I think you should be able to get just over 40mpg.

One trick I have found is when going downhill. The DSG is brilliant but will often hold a gear, our even change down a gear. If you want the gears to disengage, and it has not done it automatically, then knock it into manual then back to auto and it will go into "eco" mode, which is basically neutral. That drives up the mpg on long downhills!

 

[bob_summers]

Handy to know that, and Ihad no idea ACC increased consumption.
I will usually set the cruise to an embarrassing 100kmh/62mph - HGV speed limit is 90kmh - but the slow pace suits me most of the time.

 

[Algor]

Mine has done 1100 miles now and I have averaged mid 20's, I expect a new engine to be a little tight and milage to improve, I also drive it pretty hard as it is my daily driver and I drive it as I would a car, but I had hoped for higher. As stated above the box will change down going down a steep hill when coasting but give it a little gas and it will change up again. I fully expect high 20's/low 30's once it settles.

 

[Baldrick]

I have a 150 DSG 6.1 Ocean. Now covered just shy of 6,000 miles. Not a daily driver so when we go out it is normally on a longer run. I travel at just over 70mph, when the limit allows. Without ACC (adaptive cruise control) you will get a higher mpg. I have seen high 30s but not low 40s. However if you are travelling slightly quicker than the HGVs then I think you should be able to get just over 40mpg.

One trick I have found is when going downhill. The DSG is brilliant but will often hold a gear, our even change down a gear. If you want the gears to disengage, and it has not done it automatically, then knock it into manual then back to auto and it will go into "eco" mode, which is basically neutral. That drives up the mpg on long downhills!

I’m pretty sure there’s a Coast option within the settings (accessible whilst not driving on the steering wheel) that disengages the drive completely ie Neutral automatically when going down hill if acc is off. If you can’t find how to do it message me and I’ll find it and run you though it. Helped get a few more mpgs. We have a 204 DSG and get upper 30’s (36-39) when I drive steadily around 66-70. There’s about 25,000 miles on the clock and it has improved. A mechanic once told me that the mapping changes - on a TT at 20,000 miles so I guess similar for all/most engines. I also rarely use ACC and think (from my experience) a person’s anticipation gives higher mpg than a simple radar unless you’re on a completely deserted road which doesn’t often happen to me in the UK.

 

[subthree]

I’m pretty sure there’s a Coast option within the settings (accessible whilst not driving on the steering wheel) that disengages the drive completely ie Neutral automatically when going down hill if acc is off. If you can’t find how to do it message me and I’ll find it and run you though it. Helped get a few more mpgs. We have a 204 DSG and get upper 30’s (36-39) when I drive steadily around 66-70. There’s about 25,000 miles on the clock and it has improved. A mechanic once told me that the mapping changes - on a TT at 20,000 miles so I guess similar for all/most engines. I also rarely use ACC and think (from my experience) a person’s anticipation gives higher mpg than a simple radar unless you’re on a completely deserted road which doesn’t often happen to me in the UK.

Downhill, nine times out of ten it will go into coast automatically but on the occasions it doesn't then I flick it across. Picks up speed quickly then

 

[Cali Phillip]

I have a 150 DSG 6.1 Ocean. Now covered just shy of 6,000 miles. Not a daily driver so when we go out it is normally on a longer run. I travel at just over 70mph, when the limit allows. Without ACC (adaptive cruise control) you will get a higher mpg. I have seen high 30s but not low 40s. However if you are travelling slightly quicker than the HGVs then I think you should be able to get just over 40mpg.

One trick I have found is when going downhill. The DSG is brilliant but will often hold a gear, our even change down a gear. If you want the gears to disengage, and it has not done it automatically, then knock it into manual then back to auto and it will go into "eco" mode, which is basically neutral. That drives up the mpg on long downhills!

also set the acc to eco mode and run the tyres at 3.1bar all round.
Mines a T6 150 ocean and even round here in very twisty and hilly roads I can average 37mpg with care, peak mpg on a level route stuck behind an hgv for 20 of the 46 miles I got 54mpg.
70mph on the motorway 37mpg in winter.

 

[subthree]

also set the acc to eco mode

I think I probably just have it set in the default "normal" mode. I'll check it at the weekend. Thank you.

 

[Cali Phillip]

I think I probably just have it set in the default "normal" mode. I'll check it at the weekend. Thank you.

it holds the gears longer, off acc it seems keen to drop gears early.
I often have the acc on for the uphill and cancel for the down getting the coast mode.
I think I could do better on mpg with summer tyres ( on Goodyear vector gen 3 all seasons, small drop mpg) and without the solar panel, extra drag. probably less drag than the awning I guess.

 

[B J G]

For maximum mpg slipstream an HGV or Coach, preferably an empty one for uphill sections (if one overtakes you follow that one) you'll gain 10>20% on the mpg figure.
4MPH isn't going to change your travel time by much but beware of being classed as tailgating.

 

[Cali Phillip]

For maximum mpg slipstream an HGV or Coach, preferably an empty one for uphill sections (if one overtakes you follow that one) you'll gain 10>20% on the mpg figure.
4MPH isn't going to change your travel time by much but beware of being classed as tailgating.

let the acc take the strain

 

[Perfectos]

For maximum mpg slipstream an HGV or Coach, preferably an empty one for uphill sections (if one overtakes you follow that one) you'll gain 10>20% on the mpg figure.
4MPH isn't going to change your travel time by much but beware of being classed as tailgating.

Ahhh that takes me back to my T2 days, slip streaming lorries on the flat and down hill, only to be overtaken by HGVs going up hill

 

[Wildcamper]

How are you measuring your mpg? Full tank to full tank or the reading off the MFD display for individual trips?

 

[Perfectos]

Regarding the coasting function : does anyone have any views on long term real world efficiency particularly when coupled with other events such as DPF regen frequency with / without Coasting function turned on / off.

we know the DPF regen uses more fuel whilst the regen is running, during Regen fuel pressure is increased to aid cooling, the excess fuel being returned to the tank, during Regen the engine runs hotter and idle revs are higher, add blue consumption increases massively.

The coasting function disengages the engine / transmission allowing the engine to free wheel, albeit at an idle speed and could offer a perceived fuel saving benefit amounting to a couple of miles per gallon,
however when the engine idles it potentially creates more carbon deposits throughout the system (DPF, Catalytic converter, EGR etc). As the exhaust pressure and temperature throughout the system is reduced and therefore the idling effect could potentially affect other efficiencies of the power plant, including turbo usage.

I can see that there is potentially an upside to Coasting but are there any negatives ?
and at what point does the positive become a potential negative Coupled with potential issues such as DPF, blocked / reduced EGR tube capacity / turbo usage etc.

in an attempt to try to understand some of these questions I switched my coasting function off, the van is only being used for relatively short trips 10 - 20 miles Average. (for obvious reasons)

in that time I have noticed less frequent regens over a 2000 mile interval (notional experience), the add blue usage seems to have reduced significantly (add blue monitored via MFD vs experience of the lifetime of the vehicle usage so far: actual usage)

is the coasting function one of those tools employed by manufacturers to attain Economy figures on a brand new engine (similar to EGR system) across the spectrum of the test criteria?
does any perceived benefit out weigh long term performance over real world driving ?

would the coasting function be as effective as non coasting in all real world situations ? (particularly when measured across an extended period of real world driving environments and other contributing factors, as opposed to test environment measuring only limited factors)

and considering other factors such as Regen frequency, EGR efficiency degradation, engine oil contamination, optimal engine operating temperature, fuel economy vs actual real world emissions (not just those coming out of the exhaust during a limited test environment etc?

Whilst coasting the alternator increases charge to the batteries (charging of starter Battery etc) for very short burst, but with coasting switched off the alternator charges the batteries at a higher voltage, far more efficiently and for longer periods of time. ( I have monitored this over the same period and have experienced generally better holding voltage of the starter battery for longer periods of time with less driving / time on hook up)

is there a benefit to either only using coasting on long runs / short runs or not at all on a fully “run in“ engine?

IMO it’s a little like the start stop function, yes it can be proven to reduce emissions in a test environment when applied to a certain set of critera, but does it actually provide an across the board benefit in real world situations like it is purportedly meant to be doing When compared to other factors such as wear and tear, increased cycling of other real time events etc, which themselves can have cause and effect on the very thing they are meant to be improving ?

your thoughts?

@bob_summers

you do prompt some good debates

 

[bob_summers]

I’m going to seem like I’m trolling
Was a genuine question though!
Re tailgating, not familiar with vehicle aerodynamics but I come from road cycling and studies show that the drag reduction when drafting at 20cm is only a couple of percent higher than when drafting at 100cm ie 5x the distance. So to get a good tow off a lorry, you might not need to be so close!
If it’s on Portuguese plates it’s likely to be ignoring the 90kmh limit anyway, seems like there’s no reciprocation between France and Portugal for speeding penalties.

 

[B J G]

Ahhh that takes me back to my T2 days, slip streaming lorries on the flat and down hill, only to be overtaken by HGVs going up hill

Rope with a grapling hook?

let the acc take the strain

I don't have ACC so wonder how close or far it keeps you and does it adjust with speed? Presume that it does.

 

[Cali Phillip]

How are you measuring your mpg? Full tank to full tank or the reading off the MFD display for individual trips?

I just go off the trip 2 reset after each refill, it is always lower on the fuel and mileage, but that includes the parking heater use as well as some no doubt error from the mfd.
Given you cannot separate the parking heater use it seems reasonable, more looking at the difference not the absolute figures.

I don't have ACC so wonder how close or far it keeps you and does it adjust with speed? Presume that it does.

You can change the setting, i have it set at the furthest setting, think it adjusts distance with speed.

 

[66tim99]

let the acc take the strain

Do you set it to the closest to the vehicle in front to Max the slipstream mpg gain?

 

[bob_summers]

I’ve never used a VW ACC but the ones I’ve used just have three settings for how close you follow. Sounds gimmicky but I’ve hired cars with it and wouldn’t be without it now. It’s optional on the Spanish Calis but I specced it even at something like 750eur. Even the sales guy at the dealer didn’t know how it worked despite having it on his own car, some folk will never miss it!

 

[66tim99]

I think there are 5 distance settings now, this is a useful video

I’ve never used a VW ACC but the ones I’ve used just have three settings for how close you follow. Sounds gimmicky but I’ve hired cars with it and wouldn’t be without it now. It’s optional on the Spanish Calis but I specced it even at something like 750eur. Even the sales guy at the dealer didn’t know how it worked despite having it on his own car, some folk will never miss it!

 

[Amarillo]

On four tanks I have managed over 40mpg on brim to brim measurements. All four occasions involved substantial sections of motorway, and three of the four occasions were in a fully packed van with bikes on the tailgate.

More typically we get 35-38mpg.

Like you I enjoy my driving at a gentle pace, setting the cruise control at 58mph to keep out of the way of HGVs. I coast on downhill sections.

The MFD routinely overstates the MPG by between 2 and 5 mpg.

 

[bob_summers]

Good to know it’s possible. I had guessed the van MPG readout applied a bit of feel good factor lol so just work it out at the pump.
Eqch to their own but it feels a lot more relaxing at 100kmh than at 130, and as we have to stop fairly often anyway (I’m the sole driver and the boy needs to get out every couple of hours) there’s little point in trying to make progress!
From home to the euro tunnel it’s about 2.5h slower at 100kmh so it’s not a negligible difference - but you can’t realistically do that drive in one day with one driver and a child on board and I’m in no particular hurry to get the bed up in a motorway aire!

 

[Amarillo]

I use the app “road trip” to record refuels, there is a free version and a paid version, and we pay as I think the developer has done a good job and deserves reward.

I think recording MPG is useful because if there is a minor engine problem the first place it will show up is fuel consumption. Here’s a screenshot.

We have it set in Euros/litres/km and mpg because when we started using it we were touring Europe.

In the above you can see a dip in the MPG about two years ago. That was when we had a problem with the manifold gasket (?) At first I mistakenly thought it was because we had switched the wheels and tyres from 16” 215s to 17” 235s, so the problem remained unresolved for quite a while.

 

[B J G]

I just go off the trip 2 reset after each refill, it is always lower on the fuel and mileage, but that includes the parking heater use as well as some no doubt error from the mfd.
Given you cannot separate the parking heater use it seems reasonable, more looking at the difference not the absolute figures.


You can change the setting, i have it set at the furthest setting, think it adjusts distance with speed.

Just wondered as in the forthcoming Highway Code it has quite specific info relating to Tailgating and seemed to indicate that Motorway cameras would do both Speed and Tailgating automatic fines.

 

[66tim99]

Just wondered as in the forthcoming Highway Code it has quite specific info relating to Tailgating and seemed to indicate that Motorway cameras would do both Speed and Tailgating automatic fines.

I’ve never driven with ACC before. It does make MPG sense (I suppose?) to set it on the closest setting. I presume that is a legal (non-tailgating) distance, and if the car in front slams on the brakes, the ACC will be quicker than me at slamming on?
Incredible technology