In my 2005, coasting with ICE foot off the gas, at 44-50 MPH = 1.1L / 100km.
I'm looking at the navigation screen for this info.
Are you looking at the navigation, or green message center?
-John

 

I'm looking at the message center (don't have the nav).

-- Rick

 

I'm also looking at the message center, which I have been consistently referring to as the "dash econ gauge". I don't have nav.

 

I will have a 2007 Ford Fusion as a loaner for a few days while the A/C is replaced in my FEH. ( more on that later )

The Fusion I'm driving has nearly the same 2.3L I4 engine.
I used the SG in the Fusion for 150 miles today, in the mountains.

The Fusion, to my surprise, gets nearly the same MPG on the highway as my FEH. 33-35 MPH at 65-55 MPH over flat highways.

But what you are interested in this thread is fuel-cut mode.
Shifting to L on a downgrade will make the Fusion go open-loop and fuel cut.
Open loop was stated on the SG.
I'm positive of fuel cut because water temp fell like a rock, even though outside air was 82'F ( or more ) and I was actually using the A/C.
However, again, the SG incorrectly stated MORE fuel consumption, not zero.

Coasting in N keeps the water temp above the 190'F thermostat, but coasting in N the SG reports up to 400 MPG! RPM drops to 650.

Coasting in L with RPM 3500, water temperature fell to like 165, indicating zero fuel used, but SG reported about 40-43 MPG.

Coasting in D and 1300 RPM shows about 120 MPG on the SG.

This is for a 2007 FORD FUSION. ( non-hybrid )

 

Sean ( Screen Name 08FEH ) copied and pasted this from the 2008 owners guide:

"You may also notice during extended downhill
driving that your engine continues to run instead of shutting off.
During this “engine braking”, the engine stays on, but it’s not using any
fuel. "

I thought it also belonged in this thread.

 

gpsman1 — So, that seems to leave the 2007 FEH as the only vehicle so far that shows both fuel-cut and closed-loop at the same time! Your and econoline's experiments have confirmed this, as I understand it.

Stan

 

GaryG — Unfortunately, an open-loop indication was what Ron DeLong was going to use as the primary determining factor for indicating fuel-cut operation. Of course, open-loop by itself is not sufficient, but until now, he was unaware of any ICEs that actually indicated "closed-loop" while they were not using fuel! If the open/closed-loop signal can't be used to detect possible fuel-cut events, Ron may be unable to correct the fuel-usage errors (in LPH or GPH; and in LKH or MPG) made by ScanGauge. The problem is that modern vehicles (my TCH, and it seems your FEH too) continue to show fuel injector pulsing even when fuel-cut is in effect. This spurious "pulsing" signal leads ScanGauge to mistakenly count this as additional fuel usage. Consequently, if significant fuel-cut operation occurs, the fuel consumption will be wrong. (During the winter, this wasn't significant for my TCH during in-town driving, but it was significant during highway trips. Now, during summer, much more fuel-cut operation occurs during both types of travel, and ScanGauge's fuel-usage displays are significantly wrong.) The question is how to correct this. Some unambiguous way of determining when fuel-cut is in effect must be found from the signals in the standard OBDII data stream, namely RPM, OPEN/CLSD-LOOP, TPS, water temp, car's speed, etc. How to do this?

Stan

 

I am fairly certain that RPM is a major contributor to how the SG calculates fuel use.

MPG is always proportional to RPM. Always. ( It shouldn't be that closely related, but it is, and that's the problem.... its simplicity. )And a 2007 Ford Fusion with a traditional transmission, behaves exactly the same as a 2005 FEH, and exaclty the same as a 2008 FEH.

I do think open loop is a good, and nearly positive indicator of fuel cut, when other conditions such as engine temperature are met.
Cases of fuel-cut and closed loop are really rare, or maybe non-existent.
While people may see this, I still consider this erroneous data.
For example, I sometimes see 366 RPM on my SG when in EV mode. This is for sure false data... so it makes sense there can be other false data.

Let's look at what closed loop means:

If closed loop means sensor feedback is used to adjust the air/fuel, and there is no need for air/fuel, then there is no need for closed loop. The correct data should be, and usually is, open loop status.

I say Ron should go ahead and make the changes with a few prototypes and send them out to a few of us die-hards to "beta test" them. Perhaps we could pay him a small fee to cover his parts and shipping, but we should get them at low cost in exchange for providing him valuable feedback... feedback he cannot simulate, or calculate without the use of several cars, several different cars, in several environments.

Perfect or not, using open loop as part of a dichotomous key to determine fuel cut I think is a good idea.

-John

 

GaryG, doesn't econoline's data contradict this? gpsman1, have you and econoline resolved this inconsistency? Are you saying that you think that econoline's FEH is actually not in fuel-cut when his FEH says that it's using no fuel, and when SG says that it's closed-loop? Or, are you suggesting that Ron DeLong should ignore this possibility?

Stan

 

Stan, I get the same indication as econoline on my 2007 FEH (0.0L/KM on the dash econ gauge) pretty much every time I take my foot off the gas and coast while showing closed-loop on the SGII. If this was true fuel-cut, I really think my mileage would be higher as much as I coast. It's probably using a small amount of fuel but not enough to register. SG usually reports 120-150mpg when I coast.

John, You asked if my readings were from the nav or the dash gauge a while back (I don't have the nav). Do you think there is a difference with how the nav measures fuel consumption?

-- Rick