59 minutes ago, shyVRS245 said:

Last tank 399 miles 45.09 litres (9.92 gallons) average 40.22mpg, not bad for a 335.9bhp car.

Must have been Milton Keynes, town of a hundred roundabouts....

VW's own words on the subject for manual transmissions lifted from their leaflet:

Save as you drive.
Background information
for expert fuel savers.

 

Target zero fuel consumption.
Coasting in gear cuts off the fuel supply to the engine. This is also referred to as overrun cutoff,
and it means you're not using a single drop of fuel. This is different from coasting with the clutch
depressed, when the engine continues to tick over – which means it is still burning fuel, albeit in
very small quantities. You can easily compare your fuel consumption when coasting with the
clutch depressed and when coasting in gear. Just set your multifunction display to »current fuel
consumption« and you can see for yourself the effects of overrun cutoff.
Use overrun cutoff when:
• you want the engine to help you brake, for example when approaching a red traffic light,
• or when you're on a steep downhill gradient. Using the braking effect of the engine will
also reduce the wear on your service brakes.
But depress the clutch when:
• you want to maintain a constant speed on a long, level stretch of road, or to coast to a stop,
• or when you want to maintain or increase your speed on a gentle downhill gradient.
The biggest fuel savings with overrun cutoff are achieved around town.

Edited 12 August, 20196 yr by Gerrycan

12 hours ago, Gerrycan said:

It has been many years since I looked at the UK Highway Code but my understanding is that it is illegal to coast out of gear in a manual car,

 

Its my understanding that it carries the same penalty as walking on the cracks in the pavement and loitering with intent to use a pedestrian crossing.

 

 

Edited 12 August, 20196 yr by J.R.

49 minutes ago, Gerrycan said:

VW's own words on the subject for manual transmissions lifted from their leaflet:

Save as you drive.
Background information
for expert fuel savers.

 

Target zero fuel consumption.
Coasting in gear cuts off the fuel supply to the engine. This is also referred to as overrun cutoff,
and it means you're not using a single drop of fuel. This is different from coasting with the clutch
depressed, when the engine continues to tick over – which means it is still burning fuel, albeit in
very small quantities. You can easily compare your fuel consumption when coasting with the
clutch depressed and when coasting in gear. Just set your multifunction display to »current fuel
consumption« and you can see for yourself the effects of overrun cutoff.
Use overrun cutoff when:
• you want the engine to help you brake, for example when approaching a red traffic light,
• or when you're on a steep downhill gradient. Using the braking effect of the engine will
also reduce the wear on your service brakes.
But depress the clutch when:
• you want to maintain a constant speed on a long, level stretch of road, or to coast to a stop,
• or when you want to maintain or increase your speed on a gentle downhill gradient.
The biggest fuel savings with overrun cutoff are achieved around town.

Think xman needs to read the above as it was what I was explaining what happens in a manual car when you lift off whilst still in gear. YOU DON'T USE ANY FUEL.

24 minutes ago, J.R. said:

 

Its my understanding that it carries the same penalty as walking on the cracks in the pavement and loitering with intent to use a pedestrian crossing.

 

 

That must be some weird French by-law in Picardie.

People fight tooth and nail to gain the very desirable spots beside passage piétons to stand in groups or singly watching the world go by and being completely flummoxed when a muppet (me) stops as required by the code de la route, then they express an even more surprised and gormless expression at what they think is a driverless car with a passenger in the RH front seat!

1 hour ago, shyVRS245 said:

Think xman needs to read the above as it was what I was explaining what happens in a manual car when you lift off whilst still in gear. YOU DON'T USE ANY FUEL.

And then you have pumping (closed throttle plate) and friction losses in the engine, otherwise known as engine braking. As rightly (unusually for Shy 😉) pointed out, ANY braking = loss of kinetic energy.  So consider if the loss of kinetic energy due to engine braking minus any energy recovered exceeds the fuel burnt to maintain idle.

 

So its a bit more complicated than you might at first think. VW advice is correct in there are 2 different scenarios.

 

One benefit of ACT is a reduction in pumping losses when active.

 

 

 

 

 

Edited 12 August, 20196 yr by xman

Set a new personal record tonight in rush hour traffic in wife's 1.5TSi Karoq manual by lifting and coasting in gear (saw 300mpg on several occasions on the instant readout) but ended up with 65.1MPG. Surprised if anyone can beat  this over a similar short distance.

Edited 12 August, 20196 yr by shyVRS245
WRONG WORD

1 minute ago, shyVRS245 said:

Set a new personal record tonight in rush hour traffic in wife's 1.5TSi Karoq manual by lifting and coasting in gear (saw 300mpg on several occasions on the instant readout) but ended up with 65.1MPG. Surprised if anyone can be this over a similar short distance.

 

You'd be lucky to get 15mph average in the rush hour traffic around here.........

5 minutes ago, shyVRS245 said:

Set a new personal record tonight in rush hour traffic in wife's 1.5TSi Karoq manual by lifting and coasting in gear (saw 300mpg on several occasions on the instant readout)

I thought the display only went up to 200mpg.

 

Have you remapped that too?

Using Shy’s/NASA technique of using slingshot gravity assistance round those roundabouts no doubt.....(saving >0.5 mpg/roundabout)

 

Plus going downhill helps, I find.....

 

 

 

Edited 12 August, 20196 yr by xman

30 minutes ago, john999boy said:

I thought the display only went up to 200mpg.

 

Have you remapped that too?

Perhaps it only goes upto 200mpg on the Superb because it can't go any higher. Regularly saw between 150-250mpg but couldn't take a photo on the move for legal reasons.

10 hours ago, J.R. said:

 

Its my understanding that it carries the same penalty as walking on the cracks in the pavement and loitering with intent to use a pedestrian crossing.

 

 

As @xman clarified it was more an advisory than a law and that makes sense.

Of course it means my years of conscious rebellious lawless behaviour were in fact nothing of the kind 😞 

Just to clarify the 65mpg was achieved in Sport mode with the climate control on and set to 17C.

I have never seen mine go into D mode, looks like I need to see if I have the option to tick coasting, if I do it could help me get a bit better MPG.

 

I will report back later...

That is impressive fuel economy, a very similar journey to the one i make 3 or 4 times a week to my running club and I can get over 60 but not 65 although I could if that was my sole aim, I doubt that I could do it with an average of 40mph and definitely not in UK rush hour.

 

The only way I could equal your feat were I in the UK would be to go out at 4am on a selected route, mainly motorway without roundabouts or traffic lights and change the time on my MFD for the photo.

Had a  look today and could not find that coasting tick box.

 

I will dig out manual at some point later this week, not sure it is an option for the DSG boxes?

Same commute in the 245 Octavia identical 40 minute journey with same 40mph average speed and managed 45.2mpg.

5 hours ago, MJ1 said:

Had a  look today and could not find that coasting tick box.

 

I will dig out manual at some point later this week, not sure it is an option for the DSG boxes?

I don't have a dsg to confirm but thought from what others have said the coasting feature comes on when you select 'Eco' mode. 

Not everyone likes the general 'Eco' mode though because of associated throttle characteristics and tendency to change up at very low revs.

I believe that customising your selection of available modes to individual preferences is possible but the manual will probably have more info on how that is done.

 

Thanks Gerrycan I will have a further play today, but when I have driven eco mode I can't remember seeing it do that, but maybe I was not looking out for it.

 

Cheers

Ok so had a chance to observe eco mode and it does indeed go to E when coasting, ie foot off acceleration pedal.

 

Then back to E5 or whatever gear you happen to be in when you touch the pedal.

 

From the manual it only works in E mode and with the DSG you have to remember to select it at start of every journey. Not sure it gives much better MPG but will test further to see if I avoid using cruise that I might get better figures.