Sepp, it appears that you have researched the subject so I'll ask if you can confirm this. When coasting in neutral (or an automatic in Green Mode Drive) the engine idles, but if coasting in gear the fuel shuts off. This is how it worked on a manual transmission Golf TDI.

 

I thought I was seeing 99.9 MPG quite often in Mid Mode also because I rarely ever use the Green Mode (don't like that bogging feeling).
I wil check!

 

@Patriot! - Not sure =/ I think yes, because like Chazman just said, the car goes to 99.9 mpg even when not coasting. But I haven't seen that specifically.

@Chazman - you're right, I spent sometime watching my MPG and RPMs today, and it definitely goes up to 99.9 sometimes even when RPMs have not dipped to idle.

For instance I was in green mode + cruise control today, and watched it jump to 99.9 mpg, but stayed at ~2.1K RPM. If I turned cruise off and let my foot off the gas, it'd also go to 99.9 mpg, but the engine RPM would drop to ~800. So they've definitely got multiple things going on! And not all green mode things, might be what patriot! is getting at?

But I think I was incorrect earlier when I said the cruise control does a good job in green mode of decoupling whenever possible, I watched today and it didn't seem to do so at all (in my rather limited, 4 mile test) but started it again as soon as I turned green mode off. But it was still getting 99.9, so it may be of no concern either way.


Couple other things:
- I know the car will engine brake in auto-manual mode! Although in my trying that out, seeing I've never driven a manual personally, I think I was once overzealous in my down shifting to test it out and it just ignored my downshifts and shifted up again on its own... I assume while whispering 'Idiot' in some manner.
- Regardless of how the car is sipping fuel, its pretty impressive

 

For a manual that is correct. MINI has used the deceleration fuel cut-off for several years. The fuel will start flowing again once rpm's drop below something like 1500.

 

When in manual mode of my justa auto, i can shift sooner than drive mode would have, yielding better instant mpg reading (about 2-3 mph difference shifting). would better gas milage occur?

in Manual: 4th engages @ 20 5th @ 25 6 @ 35 ...

Also, if fuel is cut off when 99.9mpg is seen(M), and both fuel off, and N engadged (D) ....taking into account the above, what shall one do?

 

Just for curiosity...
How does engine continue to run (at idle rpm) when the fuel is cut off, like when throttle is not applied at all for coasting? So, I think it's not a complete fuel cut-off since engine has to get a tiny bit of fuel just to keep it from stalling, right? Or is the engine able to continue to spin just by its own inertia with ZERO fuel supply?
German Engineering!

 

With a manual transmission, I believe EVERY engine uses zero fuel while coasting. If you were to take into neutral, it would use a tiny bit just to idle. But while coasting, the engine is just getting spun by the wheels rolling, and requires no fuel at all to keep on spinning. And that's where the engine braking effect comes from- every pump of a piston is like a bicycle pump compressing air (slowing up that momentum of the car moving), and with no combustion, the whole thing slows the car. So you will slow down sooner in gear than in neutral, but you'll use zero fuel while doing it.

Either way, at high speeds, I'm sure it would show 99 MPG. As you come close to a stop with the gear in N, you'll see the mileage get lower and lower. A car in gear would stay 99 tho

And I have no idea how any of it works in an automatic =P

 

Again...

 

Because you are not at idle rpm. The transmission is still spinning at a high rate, which drives the engine. Thus the fuel can be cut off. When the rpm's drop low enough, the system starts to deliver fuel again and it effectively "roll starts" the engine.

 

Too confusing...

 

Very nice!

I've been getting around 35mpg in mid-mode for my drive to work. I'm happy with this, it's about what I was getting with my Veloster. I have tried green mode, but it really feels so luggy to me that I can't handle it. Maybe if I am just cruising along on a trip like you did I'd be ok with it. I just like my zip otherwise!

 

DeepBlueMCS is referring to an automatic transmission.

I am talking about a manual transmission.

 

I've been loving green mode more and more (justa here), it only feels like you're severely bogged down if you push it too hard. I feel like it is intentionally trying to keep the turbo from spooling up. Sport mode seems like such a waste for my commute.

I've been getting 38-39 mpg religiously on commute tanks and 42-43 on long trips. I'd probably get better if I didn't get so impatient with slow drivers.

 

When I drive in the green mode carefully a picture of Al Gore comes up on the cover art of whatever album I'm playing and says "thanks Big Newt" when I'm playing The Hanging Chads. Does anybody else's do that?

 

Recently did quite a few miles in town (city driving - no highway) and mpg meter was tagging 33 mpg.

 

less than 100 mi on the car and all city street driving.