Euro 6 compliance - reduced MPG ?

[WhatHappenedThere]

TL:DR - should a new like for like A6 do 20% less mpg than an old one ??


I'm hoping that some knowledge can be found on this site -

Currently running a 2016 A6 Avant AllRoad Sport (272ps V6 3.0D)
I traded my 2014 A6 Avant AllRoad (215ps V6 3.0D) against it.


I regularly do a 50mile journey to the OH's up the A1. 50 miles with a little B-Road at each end.
The 2014 model when nursed could reach just 51mpg in E mode etc.
This new 2016 model will barely get over 41mpg. Same route. Same driving (nursing) mode.

How can this be I have been trying to work out, and why I decided after lengthy lurker to register on PH forums. Yes the engine has a little more poke, but more or less the same unit.
Old car had 19 inch Michelin CC's on, this new one 20 inch PZero's
New Car also drinks AdBlue fwiw

Tyre pressures are fine - I've even put them up a touch.

I took it in to Audi today (appointment for it to go in the workshop, rather than a walk in) to see if there is anything wrong / settings, reboot or flash of the ECU having been effected by the previous drivers style etc ....
the lad on the desk came back to me suggesting this colder weather this time of year could make the difference.

I questioned this 20% difference..... he mumbled something and called me 'mate' in the process. FFS.

The lead tech came out and we had some craic and tried to work it out. All he can suggest is in the aftermath of the Emissions scandals and the EURO6 compliance is the cause of the lesser MPG.

The car seems to be fine pottering around and up to 50, but once at cruise (on cruise) at circa 75, it just wont see anything above 41mpg.


Thoughts?
Experience of the newer breed of EURO 6 ?

[WhatHappenedThere]

Mmm- moved.

And Also I don't think it is a Euro6 is it ?

[WonkeyDonkey]

Colder weather does do this. Longer to get up temp, larger draw on alternator, different diesel mix to prevent jellying.

Also you've bought a VAG product post dieselgate. You're previous product was manufactured before they were tore a new ahole.

Your tyres in will also be causing greater rolling resistance.

[WhatHappenedThere]

WonkeyDonkey said:

Colder weather does do this. Longer to get up temp, larger draw on alternator, different diesel mix to prevent jellying.

This is a red herring as ran them back to back and the 'old one' throughout winter was doing the circa 50mpg. Newew one in the so called spring, no where close.

WonkeyDonkey said:

Also you've bought a VAG product post dieselgate. You're previous product was manufactured before they were tore a new ahole.

So it falls to this :

Dieselgate. How will this in reality effect MPG (as opposed to fudging the emissions numbers)

[essayer]

Is it really like for like when the new car is 272 vs 215bhp?

[Scrump]

I have heard tales that the euro vi Mercedes 3.0d give a bit worse mpg than the similar euro v models.
Not sure how much truth there is in it as people are often comparing a run in higher mileage car with a new low mileage one and also the newer cars tend to come with larger tyres.

[Sheepshanks]

WhatHappenedThere said:

Mmm- moved.

And Also I don't think it is a Euro6 is it ?

It will be Euro 6 - everthing from Sept 15 has to be.


Assuming there's nothing dragging in the brakes / transmission (does the car roll OK?) I suppose it could be a cumulative effect of a whole bunch of things - different engine / gearbox set up for Euro 6 so maybe the journey doesn't suit the car in the same way. Bigger wheels / tyres, cold weather, winter diesel.

Have you checked actual MPG, not just what the computer says?

The other thing is cars vary - the MPG you were getting in your old A6 seems remarkably good. I've got an old Merc C270CDi - I would never see 50+ MPG on a 50 mile journey, but I will if it's 100 miles+ of very steady motorway driving. I've never had 50MPG on the display of wife's DSG 4Motion Tiguan.

[WhatHappenedThere]

essayer said:

Is it really like for like when the new car is 272 vs 215bhp?

Pretty much everything is yes. Same unit, volume etc, with a bit more tune. I would of course expect a differnce when booting it along, but when intentionally trying to hyper mile or whatever the term is ... I am shocked to see a 20% differencein the car and tech.

For example . the new car 'coasts' knocking it out of gear when foot is off the accelerator.

The noticeable difference in MPG is at cruise at 70 - 75 mph. Hardly asking much from (either) engine)

[WhatHappenedThere]

Sheepshanks said:

Have you checked actual MPG, not just what the computer says?

The other thing is cars vary - the MPG you were getting in your old A6 seems remarkably good. I've got an old Merc C270CDi - I would never see 50+ MPG on a 50 mile journey, but I will if it's 100 miles+ of very steady motorway driving. I've never had 50MPG on the display of wife's DSG 4Motion Tiguan.

As above - 50mpg when trying to be conservative but still keeping with traffic.
The Tech suggested that I do a real 'brim tank' type calculation rather than the OBC, which I will.

[WhatHappenedThere]

as a complete aside the AllRoad i bought was fully loaded with everything from the previous owner except the touchless entry from what I see. Self closing doors, panny roof, tech pack / phone cradle, auto park - with lovely cream leather seats and in the bronze metallic brown colour.

I wondered if stupid buying a '66 plate car at £31k vs a new A6 factory fresh.

I sat in the new ones in the showroom with poverty spec seats it felt (no moveable thigh supports) and I did not doubt my decision at all. The A6 looks bang for buck at those showroom prices but I am not convinced in the quality of the S-Line I sat in.

[Sheepshanks]

WhatHappenedThere said:

For example . the new car 'coasts' knocking it out of gear when foot is off the accelerator.

To some extent, it's swings and roundabouts - when coasting the engine needs fuel to keep it ticking over. If you just let the car slow on the over-run, fuel is shut off.

WhatHappenedThere said:

The noticeable difference in MPG is at cruise at 70 - 75 mph. Hardly asking much from (either) engine)

There ought to be an easily repeatable test to measure MPG, with a reasonable tolerance.

[threadlock]

WhatHappenedThere said:

The Tech suggested that I do a real 'brim tank' type calculation rather than the OBC, which I will.

Is your frustration based entirely on the OBC's calculations in each car? If you're not brim-to-brim calculating it at the pump then all bets are off. Your newer model is probably just more accurately calculating mpg and the old was optimistic.

[Marcellus]

What’s the weight difference between an A4 and an A6?

Also difference in drag of the larger body and are the tyre widths the same or are they wider on the A6.

All of which will reduce mpg.

[anonymous-user]

Tight engine? What is the mileage on the new and old cars?

[threadlock]

Marcellus said:

What’s the weight difference between an A4 and an A6?

RTFOP

[Marcellus]

threadlock said:

Marcellus said:

What’s the weight difference between an A4 and an A6?

RTFOP

hmmmm funnily enough i did re-read it twice before I posted and was sure it said traded in A4 for an A6 which is why I posted, perhaps I was wrong or perhaps the OP was edited to say A6 to A6.

[Glasgowrob]

time for a remap OP if it bothers you that much

and by that i dont mean flashed by some "mapper" out the back of a van, speak to one of the known vag specialists MRC APR Ecotune depending on your location result being most likely a noticeable gain in mpg(10-12% is not uncommon along side a whole boat load of more grunt when you want it

[WhatHappenedThere]

Marcellus said:

threadlock said:

Marcellus said:

What’s the weight difference between an A4 and an A6?

RTFOP

hmmmm funnily enough i did re-read it twice before I posted and was sure it said traded in A4 for an A6 which is why I posted, perhaps I was wrong or perhaps the OP was edited to say A6 to A6.

Apols for the silence - new registered members are banned from posting in the 'drinking hours' it seems.

NoMarcellus - a s straight A6 AllRoad to A6 AllRoad Sport.
No editing of the post.

[WhatHappenedThere]

gottans said:

Tight engine? What is the mileage on the new and old cars?

Old engine was circa 45,000,
New engine 13,000

I did wonder that too, but hells teeth - 13,000 has an engine found its groove surely ?


I did question whether there was any internal learning of the ECU maybe married to the way the orginal owner drove it - Audi tech says no, and it adapts in time, not needing a 'reset' to wipe any previous habits.

[WhatHappenedThere]

Glasgowrob said:

time for a remap OP if it bothers you that much

and by that i dont mean flashed by some "mapper" out the back of a van, speak to one of the known vag specialists MRC APR Ecotune depending on your location result being most likely a noticeable gain in mpg(10-12% is not uncommon along side a whole boat load of more grunt when you want it

Hmm, possibly, however this move from the old to the new was caused by a sudden exposure to a void or lack of warranty cover on the gearbox.... this new car has Warranty until end of 2020.
I am very very unlikely to do anything to effect its validity