John, I should have mentioned that. Yes, engine was completely warmed up, and would eventually go ICE-off as I continued to coast.

 

Don- do you feel, is your gut instinct, that you are getting a correct indication, or a false one?

Something must be different. Either in the SG or in the 2007 car.
You say it is easy to do, and I can't repeat that no matter how hard I try.
If you got it once in a while, I would say it happens in only a rare circumstance, and I can't find that circumstance. But now you say it's not rare. If it is not rare, then how come I never see it. This is the big question.

Tonite, on a cold engine at ~44MPH:
Coasting in L with lots of regen: Closed Loop / ~1100 RPM / 1.7L / 100km
Coasting in D with little regen: Closed Loop / 1300 RPM / 3.5L / 100km

On a warm engine:
Coasting in L at slow speed with lots of regen = ICE shutdown
Coasting in L at high speed with lots of regen = ICE runup / open loop / ~4000 RPM / 0.0L / 100km
Coasting in D with little regen = Closed Loop / ~1100 RPM / 1.5L / 100km

I learned tonite I can run the A/C from electricity only.
Even during engine runup to 4000 RPM, and 0.0L / 100km being burned, the AC compressor still cycles as usual. Obviously, the mechanical belt is still turning the A/C compressor, but that belt is being turned by electricity, not gas! ( electricity is turning the ICE, the ICE is turning the belt )

The only time I get 0.0L / 100 km (aka 'fuel cut' ) is with Open Loop on the SG.

It is not out of the question that the 2007 is different. I got the 2005 which was Ford's first shot at... well... everything!

That being said, please double check all the settings in your ScanGuage also, since once or twice I had mine get set to factory defaults without my knowledge. Be sure you have the correct engine size, and gas type ( Hybrid).

I'm puzzled, but does it make any sense to have closed loop and fuel-cut at the same time? Maybe if we can determine why this would, or would not happen, we can surmise how likely it is really occurring.
-John

 

I have a 2007 FWD FEH, so I'll do some more testing are report back. Perhaps it is a difference with the model years. The testing I did before was only after I had a run-up. If there's a way to get true fuel cut with out the run up, I'm definitely interested!

Don, does the fuel flow go to 0.0 L/KM on the dash gage right after you let off the gas, or does the RPM have to get down to ~1100 before it goes to 0? Also, what approx speed were you starting at?

Thanks,

Rick

 

Rick, I've tried this at various speeds normally encountered in city driving. Speed would typically be 35mph, I'd let off the gas completely, engine continues to run (about 1100 rpm), immediately reset dash econ gauge and see 0.0L/KM. I'd continue to reset the econ gauge every few seconds during the coast and continue to observe the 0.0L/KM. Closed loop during all of the above.

I'll recheck the SG setup as John requested.

My gut feeling is that the vehicle is not in fuel-cut mode, the dash econ gauge simply isn't registering the small amount of fuel being consumed during the coast. Perhaps there is a lower threshold on the gauge indication or it is simply zeroed under the conditions of the coast.

 

This seems like a stupid question but I'll ask and look like an idiot....What happens if you DON'T keep resetting it every few seconds? If it starts to register a value then isn't whats happening just that you are resetting the counter before enough fuel has flowed past it to register one "tick" on the meter?

 

Good point. The initial reset is required to clear the accumulated average mileage that was on the gauge and zero it. Perhaps I should not reset it again once I start the coast, although I have never seen a value (other than 0.0) before a reset. But you may be exactly right, and I'm clearing an accumulating value before it can display. I'll try that again this weekend and report back.

 

Good Point Tim. ( Teester )

However, I do not think this is the case.

We are measuring instant fuel RATE ( speed of use ) not fuel consumption ( liters).
If it were the second case, consumption, I'd say you were right on.

The rate of consumption is measured and reported about once every second. I doubt anyone is zeroing the display at 1 Hz. But it's worth a minute of effort to rule it out.
-John

 

I tried this quite a few times at various speeds tonight and had the same results as Don. After letting off the gas, and starting to coast, I reset the dash gauge and it registered 0.0L/KM and closed loop on the SG II for the entire coast (except when I slowed enough to go EV ... the SG then went to open loop).

I started at speeds of 45 to 50mph and it was the same every time (RPM around 1100). It even registered 0.0L/KM when going 65mph on the interstate (RPM was around 1350).

This must be something different on the newer models. I suspect it's not true fuel cut though. Perhaps this is part of the reason my SG consistently reports ave mpg 1 to 2 lower than the ave on the dash gauge?

-- Rick

 

So we can say with some confidence the 2007 displays info differently than the 2005. If it really cuts fuel with every coast ( let off the gas ) then that would be a very attractive feature, and an improvement over the 2005's.

I think this is totally possible, and desireable.

However, to me, this would mean the 2007's would get significantly better gas mileage. Enough to say, move the EPA rating one or two MPG upwards from the 2005. To the best of my knowledge, the EPA fuel economy rating stayed the same from 2005 to 2007. Maybe they were lazy and didn't retest? Okay, then that would mean real drivers in real world conditions would report better FE in a 2007. I don't think that is the case either. Is it?

How can we be certain of fuel cut?
-John

 

John, I would agree that's it's more than likely not fuel cut. I'm pretty happy with my recent mpg, but with as much coasting as I do I think it would be a lot better!

As I mentioned, my SG II consistently comes up 1 to 2 mpg less than ave mpg on the dash. The SG is also pretty close to what I calculate by hand when looking over several tanks. If I'm erroneously reading 0.0L/KM when coasting, perhaps this is part of the reason for the difference.

-- Rick