Here's an interesting one for you... and it may be a quirk of the combination of DSG + the 1.4tsi Cylinder-on-Demand engine.

 

On the school run this morning, I decided to try a bit of experimenting now that I've done my first 500 miles nice and gently. So on the way there, I drove in Eco mode (as I have been doing all the time) and kept half an eye on the consumption readout - and it was mostly around the low to middle 30s. On the way back, however, I put it in Sport mode, and the readout was mostly above 40.

 

The road is a 50mph A-road which flows freely and is pretty flat, and I go about 3 miles along it. Before I get there on the way to school, I have a short (1.5mile) dual-carriageway bit, so the engine was warmed up (so I'm discounting that for now). What I did notice is that because Sport holds a lower gear and higher revs, it was quite happy doing 50mph in 4th at somewhere between 2.5-3k revs. In Eco, it does 50mph in 6th at less than or around 2k.

 

Now here's the interesting thing - the CoD only kicked in at certain points when in Eco mode, but it was on pretty much all the time in Sport. My assumption is that this is because it works at low load but high revs. Therefore, the engine was being more economical in 2-cylinder mode at higher revs than it was in full-fat 4-cylinder mode at lower revs. But the Eco setting in the gearbox doesn't seem to appreciate this.

 

Admittedly, I need to relearn how to drive a car, because coming from a manual diesel where I rarely went over 2-2.5k revs even when accelerating to a DSG petrol is just killing my muscle memory - but this short experiment makes it seem like the combination could be a lot 'smarter' and the traditional Eco mode of the engine (throttle!) and particularly the gearbox may not actually be the most economical when it comes to these new CoD engines.

 

I'm also going to have to do some more experimenting to see if I can repeat this on other (and longer) journeys.

If you drive the first 5 miles until the oil is at efficient operating temperature in one mode does it not show less MPG than the next 5 miles when the oil is above an indicated 50*oC going up to 80-90*oC.

After 10 miles in any mode does the Average MPG not improve as the miles rack up?

 

Do it tomorrow both ways in Eco, then the next day in 'S',  do it just in 'D'. 

Engine temperature may well have had more of an influence than you might think.

 

Even with a petrol the engine, in these current ambient temperatures the engine is unlikely to be up to full operating temperature after 4.5 miles.

 

The temp gauge on the dash is coolant temp, which reaches 90 degrees Celsius quite quickly, but the oil temperature usually takes quite a bit more time to reach the same temperature.

 

I'd be tempted to experiment again after giving the engine a little longer to warm up as suggested above.

 

Edited 13 March, 20188 yr by silver1011

+1

 

The coolant might show 90c but your oil is still probably 50-60c and the cooler air temps will give you 15-20% economy. It usually takes me 7-8 miles on a free-flowing A road to get up to 80c. Eco and sport don't seem to do anything for economy , it just gives a sluggush throttle response. 

Engine/oil temp, wind speed/direction, less weight in the car on return trip, c/c working hard to get the cabin to correct temp, etc etc

Lots of variables involved, as above, do the same test over a matter of days and do the whole journey in the same mode each time.  

^^^ 
All of the above.

 

Then there is almost no engine like a 1.4TSI / TFSI be it ACT /COD or just Turbo or Twincharger that is affected by Ambient Temps / Wind etc.

Also the NEW CAR, New tyres, New Brake Parts not worn in, 

new Factory filled oil, etc etc .. 

'Drive it in', (Run in),  get to know the modes of the DSG and quirks of the  Active Cylinder Technology / Cylinder on demand,. 

use 95 ron Unleaded see what MPG's you get, then give it a treat buy 99 ron minimum Super Unleaded and let it enjoy those trips running efficiently.

(Only 5 pence a litre more at Tesco with Momentum 99, or maybe Costco, or pay too much at Shell.)

I'm driving in S all the time because it keeps the engine in the proper RPM range (between 1500-2500) with normal driving and is very swift when pushed hard, very reactive throttle pedal, always shifts before 3000 RPM even when pushed harder (not floor it :P) . Only switch it to D when on the motorway. Tried it in D in town and on B roads and it kept upshifting to 1000 RPM, where you could hear/feel the engine struggling - THIS ISN'T GOOD FOR ANY ENGINE! Plus the throttle pedal  is too mushy.

 

ECO mode is unberable, tried it couple of time but when you coast you need to keep your foot on the gas because due to wind resistance and rolling drag (4x4) you lose speed very fast so no affect.

 

I have a 2.0 TDI with 140kw/190ps and i'm doing between 6.5 - 7L/100km (41 MPG) when driving briskly, drops to 6.4 L/100km (44 MPG) in town driving (very surprised, keeping RPM between 1500 to 2000) but goes up to 7.4L/100km (39 MPG) when driving on the highway at 140-160 km/h (2400 RPM).

 

Very satisfied with the engine/gearbox configuration, no jerky moments with the DSG (put it in S and leave it there because D shifts TOO SOON!) and love the auto-downshifts on hill and when braking (not like conventional autos), now if only they would do something about the door plastics.....

Had to do a few (30+) extra miles this morning before the school run, so by the time I did my experiment down the same road, the engine was well and truly warmed up.

 

Same results - ECO mode in 6th at lower rpm, 2cyl mode didn't activate often. SPORT mode in 4th at higher rpm, 2cyl mode on pretty much constantly.

 

However, because the engine had warmed up, the difference in consumption was a bit less apparent - mid-high 30s this time in ECO, and low-mid 40s in SPORT.

McGyles,

Every trip in every vehicle is a discovery.  (even not if driving a Discovery.)

But comparing a 2.0TDI / DSG and a 1.4 TSI ACT / DSG really is comparing apples and pears.

 

Driving a 1.5TSI EVO /DSG is again something different, why they are being introduced.

Edited 14 March, 20188 yr by AwaoffSki

I thought this sounded mad, but I've had similar results in my 1.5 DSG karoq. Not scientific, but so far I'm finding that, when driving 60 or under, sports mode beats eco mode!

As @WiggosSideburns says, the 2 cylinder mode kicks in all the time. 

70 or above and the difference seems to go away.

Revs around 2000 seems to trigger the ACT.

Active Cylinder Technology / Cylinder on demand. 

 So simples,  All Cylinders if the engine / load demand needs the power, shut down and use the PS / Nm required only to the demand of the drivers right foot (left if a right foot amputee.. or maybe the hand controls. ) or the Cruise Control etc...