After reading a long thread on here about the MPGs Octy 1.4 TSi owners were getting, I tried an experiment and switched to using D (Normal) mode instead of E (Eco) mode all the time. Surprisingly not only did it not worsen my fuel economy but in actual fact I got better MPG in D than in E!

 

My journeys are all mostly very stop-start on congested 30-40 mph limit roads, perhaps D mode suits these roads better? I'll certainly be sticking to D mode now as the crisp throttle response is too addictive compared to E mode and if there's no fuel consumption benefit, what's the point of punishing myself?

 

On another tangentially related note, a recent long journey from Southampton to Glasgow and back produced 52+MPG (calculated from actual fuel used). I was very impressed to get such good figures from a petrol, especially one that still brings a smile to my face when the torque kicks in. My normal journeys produce 34 MPG or so.

Edited 22 June, 20187 yr by Lingnoi
Missing word

In my opinion there isn't a major improvement in fuel economy from using eco over other modes. The biggest factors on mpg after planning ahead and restraining your right foot are ones outside of your control (traffic conditions, wind speed/direction, getting lucky with traffic lights etc.).

 

My regular morning commute is the same distance, light traffic and I stick my cruise control on at exactly the same speed each day. However by the time I arrive at work, my MPG can be anywhere between 39-43 on different days. That's in the same mode too. It's almost impossible to accurately compare the differences between driving modes because the external factors above have a bigger effect and no two journeys are ever 100% the same.

Edited 22 June, 20187 yr by ahenners

@Lingnoi - Why would you think that "eco" mode can necessarily drive better than you can if you think ahead?

ECO encourages a different driving style. If someone expects the same acceleration times under ECO then they're going to use more fuel than if the car was left in normal. If they ignore the gear change indicator, they're going to use more fuel than if left in normal. ECO does work, it's the driver that doesn't 

 

18 minutes ago, KenONeill said:

@Lingnoi - Why would you think that "eco" mode can necessarily drive better than you can if you think ahead?

Freewheeling in neutral when you lift off. Reduced power consumption from the AC etc. Gentler throttle response.

13 minutes ago, Scot5 said:

ECO encourages a different driving style. If someone expects the same acceleration times under ECO then they're going to use more fuel than if the car was left in normal. If they ignore the gear change indicator, they're going to use more fuel than if left in normal. ECO does work, it's the driver that doesn't 

 

I actually drive very gently which was why I was surprised that D was more fuel efficient than E.

 

No gear change indicator, it's a DSG.

36 minutes ago, ahenners said:

In my opinion there isn't a major improvement in fuel economy from using eco over other modes. The biggest factors on mpg after planning ahead and restraining your right foot are ones outside of your control (traffic conditions, wind speed/direction, getting lucky with traffic lights etc.).

 

My regular morning commute is the same distance, light traffic and I stick my cruise control on at exactly the same speed each day. However by the time I arrive at work, my MPG can be anywhere between 39-43 on different days. That's in the same mode too. It's almost impossible to accurately compare the differences between driving modes because the external factors above have a bigger effect and no two journeys are ever 100% the same.

Agreed. I use cruise all the time as it saves me looking at the speedometer every few seconds and I know I shan't accidently drift over the limit and get caught by a speed camera (there are lots on my route to work).

 

When I do the commute route outside normal hours e.g. very late at night I get 40+ MPG every time because of no traffic and I'm able to cruise along without all the slowing down, braking, accelerating etc

I didn't think the Eco mode was any good when I tested. It's a bit of an odd one, since yes when you lift off the throttle it does put the car into neutral and idles.  

 

I was always of the impression that when you let off the gas in any car since they moved to injection this resulted in the fuel being cut off to the injectors since the movement of the car kept the engine ticking over. No wasted fuel.

 

Only when you came to a stop or dip the clutch did the fuel supply return to ensure Idling.

 

With Eco mode dropping it to idle and not in gear, wouldn't this require the engine to keep fueling the car to keep it ticking over?

 

It's an odd one. You can tell there is less resistance when you coast, but would there be any gains?  At least when you dab the brakes it does engage the gear again for engine braking.

 

 

4 minutes ago, Plantman said:

With Eco mode dropping it to idle and not in gear, wouldn't this require the engine to keep fueling the car to keep it ticking over?

Yes, when you lift off the throttle and the engine revs are above 1400rpm (typically) the fuel supply is cutoff completely so no fuel is used, however at idle the engine is fuelled to maintain it at tickover.

 

So coasting (e.g. going downhill) with the engine above 1400rpm uses no fuel, but with the engine at idle (e.g. Eco mode on a DSG) then fuel is burnt.

Edited 22 June, 20187 yr by SWBoy

Odd one isn't it. VAG must have performed some testing on this mode to deem it worth including...unless its more of a psychological mode, so you also drive more economical too, which is where you see the gains...

Just now, Plantman said:

Odd one isn't it. VAG must have performed some testing on this mode to deem it worth including

Maybe they tested it the same way they did the dieselgate "cheat"?

 

Or maybe they just include 'Eco' because it gives better figures on the soon to be phased out economy and emissions tests?

Haha, you could be bang on there!

 

Re 'ECO', 

 Funnily non 'Eco' tyres can last longer than ECO Tyres, give better traction and actually not use more fuel or have more emissions emitted.

So actually are better value to the cars owners / drivers.

 

Vorsprung Durch Technik,  Advancements in Technology that suits 'testing' inside buildings under controlled conditions and nothing to do with real world.

http://skoda.co.uk/pages/fuel-consumption-statement.aspx

2 hours ago, Lingnoi said:

I actually drive very gently which was why I was surprised that D was more fuel efficient than E.

 

No gear change indicator, it's a DSG.

 

You said you tried an experiment. Can you explain how you conducted this and over how long?

4 minutes ago, Scot5 said:

 

You said you tried an experiment. Can you explain how you conducted this and over how long?

I previously drove using E all the time and I've been using D for about 6 weeks instead.

Most manufacturers now seem to agree that coasting uses less fuel than shutting the fuel off when in gear.

 

Coasting uses minimum fuel when the engine is at idle but you have no engine braking slowing the car down so the pay off on average is better.

 

That's why VAG engineered coasting into the DSG and manufacturers like ZF introduced coasting into the GEN2 ZF8HP on the request of BMW.

 

 

The 1.5TSI EVO can disengage the gears / drive and shut down the engine while coasting, not just shut down 2 cylinders.  

Something they have been working towards for over a decade now in dribs and drabs.

 

Edited 22 June, 20187 yr by Offski

It all depends on the situation: coasting in neutral is better if you don't want to slow down. If you do want to slow down then engine braking in gear is better, and this is exactly what the DSG in eco mode gives you.

2 hours ago, Plantman said:

Odd one isn't it. VAG must have performed some testing on this mode to deem it worth including...unless its more of a psychological mode, so you also drive more economical too, which is where you see the gains...

****s, it's not ECO for Economy it's ECO for Ecological 

 

There are theoretically less emissions when the car is driven in ECO mode & I have to say after 42k miles in my old one, it's Fn boring driving in ECO

2 hours ago, Rodge said:

If you do want to slow down then engine braking in gear is better, and this is exactly what the DSG in eco mode gives you.

Surely in ECO mode the DSG disengages the clutches and provides zero engine braking - which is why the engine is at idle?

Exactly, happy rolling along and if there is enough steepness of a descent going back into gear.

Edited 22 June, 20187 yr by Offski

30 minutes ago, SWBoy said:

Surely in ECO mode the DSG disengages the clutches and provides zero engine braking - which is why the engine is at idle?

 

If speed increases due to steepness of incline or as soon as the brakes are touched the clutches re-engage.

 

11 hours ago, Plantman said:

Odd one isn't it. VAG must have performed some testing on this mode to deem it worth including.

I'm sure they have done the maths and calculated that coasting saves more fuel.

My impression, especially on a familiar journey where I know where I can lift off and let it coast is that it does save fuel, especially on A roads where your engine may be using fuel to idle but you're travelling at 50/60 mph for a decent length of time. 
It felt odd at first but all that kinetic energy can take you a long way compared to engine braking which slows you down quite quickly.

The problem I have with eco is that you have to keep on turning it back on every time you start the car to get the dsg into eco mode! 

2 hours ago, Novascape said:

The problem I have with eco is that you have to keep on turning it back on every time you start the car to get the dsg into eco mode! 

Mine works differently. It remembers and stays in Eco.