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I've been driving and doing my best to pulse/glide with some success.

One thing I have noticed is that sometimes, when I shift into Neutral, the engine RPM will drop to near zero, and I'll be coasting with the FE gauge at 60+. Initally, it will bounce between 50 and 60, but then will jump up to 60+.

The screen shows the engine is still running, and drop big energy (as denoted by the width of the energy flow on the screen) to the electric motor, which is charging the battery. So, I'm in a Neutral pulse/glide, with the RPMS near zero, sending all that charge to the battery.

I believe this occurred when I shifted into Neutral around 50 MPH.

Does anyone with a Fusion Hybrid have this come up? Am I getting any benefit from this, other than charging the battery??

Double check the speed -- this sounds similar to the draw I noticed in a N glide between 40 and 47mph in my wife's car last night. If you exceed 47mph in N it should turn the engine on but if you shift in at 50 it might just finish turning "off" during the RPM drop because you hit 47.

By the way, the draw disappears as you drop below 40mph. I'm thinking this is similar to Warp Stealth in a Prius where the engine has to spin to keep the traction motor from exceeding its RPM limits but doesn't have to have the injectors on. The current draw is from spinning the engine with no gas (similar to the really constrained EV mode in current model Honda Hybrids which have no choice but to turn the engine when in "EV" mode).

Double check the speed -- this sounds similar to the draw I noticed in a N glide between 40 and 47mph in my wife's car last night. If you exceed 47mph in N it should turn the engine on but if you shift in at 50 it might just finish turning "off" during the RPM drop because you hit 47.

By the way, the draw disappears as you drop below 40mph. I'm thinking this is similar to Warp Stealth in a Prius where the engine has to spin to keep the traction motor from exceeding its RPM limits but doesn't have to have the injectors on. The current draw is from spinning the engine with no gas (similar to the really constrained EV mode in current model Honda Hybrids which have no choice but to turn the engine when in "EV" mode).

This is some strange behavior that I don't see in my '09 FEH. My engine does not start ever when I shift to "N" below or above 40mph because the engine will not shutdown above 40mph. As far as the eCVT, in neutral, no power goes into or out of the electric motors (except for starting the engine) because they are freewheeling. If there is no RPM's, the engine is not in fuel-cut and the electric motors are not using power to turn the engine. The wheels are the only thing that cause MG2 to power MG1 to hold an idle during fuel-cut in "D" and "L". The engine will start from EV with DFSO if you shift to "L" for engine braking.

The big power drop in "N" this guy is seeing may be the A/C compressor because there is no regen in neutral. The power is coming from the battery in neutral and that's why I know to allow for this power drop after I shift to a neutral glide. All the sensors, electronics, gauges and pumps use a lot of power from the HV battery and when you shift to neutral, you cut-off the generators from providing power to the battery. Battery management has to be a part of the scheme and I keep full control of it with everything I know about the Ford system.

I'm always open to new changes but this is how my system works. When I P&G above EV range I use fuel-cut in "D" for the glide.

GaryG

Hi, Gary -- I was referring to coasting with the engine off in N below the top EV speed downhill and up through the top EV speed. Once that threshold has been crossed the engine will turn on.

As for the draw -- I had the HVAC system completely off yet every time I entered EV mode over 40mph and then put the shifter into N the current draw continued until the speed dropped under 40mph. In the FFH you can see this on the battery visual as it overlays an arrow at the top of the (vertical) gauge to indicate charging and one at the bottom to indicate discharging.

I agree about the freewheeling bit, but there is still an RPM limit on the motors (those bearings do have a rating ;)). My limited understanding is that when you are freewheeling or running EV only one of the motors (the generator one?) is spinning backwards at a pretty high speed -- faster than the traction motor (which is spinning forward). (Somebody correct me if I'm totally putting my foot in my mouth here!!! :eek:) The top EV speed in both the Prius and the FEH was set with a particular "safe" RPM in mind and if you were to go faster the backward spinning motor would exceed that level. To avoid that, the engine must turn in order to reduce the RPM of that motor. (I've stared at the animations for the eCVT several times and still don't really understand it, but that gearset works this way in some fashion...)

In the Prius, the car burns battery to spin the engine without fuel so that the motor RPM is kept in the safe range. In the FEH, the engine is just turned on. The result is that you can put the Prius in N while in EV and coast to faster than 40mph without it coming back on (so called "Warp Neutral")... you can't in the FEH.

My theory is that the RPM limit is the same in the FFH and that it simply turns the engine to avoid harmfully high RPM in the non-traction motor while doing EV between 40mph and 47mph. The car is not programmed to do this at higher than 47mph probably because it would take a rather high current draw to accomplish... though the Prius will do it at higher speeds if the SoC is really high ("Warp Stealth").

Hopefully I didn't botch that explanation too badly.

I think I'll go look up those animations again... :o

I now understand what you are saying and that makes sense. I had thought that Ford put a higher drive ratio to get 47mph in EV in the FFH and 44 in EV in the '10 FEH but I guess I'm wrong. The only other question is how does the engine spin without the RPM gauge showing it? Or does it show a little higher RPM's but just not a idle?

GaryG

According to Al's (Hobbit's) page on Warp Stealth (see http://www.techno-fandom.org/~hobbit/cars/warpstealth.html ) it does have a measurable RPM in the Prius. I haven't actually tried to check it in the FFH yet because I don't normally have the Tach graphic showing. I know there is one in one of the screen selections so I'll have to try that the next time I get a chance to drive the car.

The energy demand gauge just drops to zero when in N so you can't tell what the RPM is from that...

I just had another unexpected opportunity to drive the FFH and have a few observations. The route I took had sections of 50mph limited roads -- it seems the higher the speed the higher the car likes to have the SoC for steady state cruising. It is perfectly capable of well over 50mpg cruising at 50mph but getting to that level was never achieved because I didn't get the SoC high enough for it. At lower speeds with P&G, the SoC has to drop for best results... and the car will reinforce that by increasing assist affinity for lower speed accelerations.

It looks to me as though in order to get the maximum FE on a route with highway one should build the SoC as high as possible right before needing to do the high speed driving. With a lower SoC you can accelerate without assist while also charging but the instantaneous when at cruising speed will be significantly lower until the car finishes charging to the level it wishes to have. It would take me a while to determine what the best balance for that would be as I have no feel for what SoC is "needed" for zero energy flow cruising at various speeds.

I cycled through the screens until I found the one with an RPM readout -- unfortunately, the tach display gets replaced with an EV bar (separate from the SoC bar) when the car turns off the engine so I wasn't able to see if the engine was spinning above 40mph when in EV mode.

If you are interested, the drive out was 52.2mpg over 9.8mi (with a warmup hit), 69.1mpg over 10.3mi back to within a few miles of the house for another stop, and finally 57.9mpg over 2.3mi back to the house. There is a lot of room for improvement in those numbers, but it is getting better. (The second leg of the trip was significantly higher because I avoided the worst stop and go section of the route by using the same bypass I utilize when traveling to and from Church from my home.) Max speed attained today was 50mph.

The round trip ended up being 59.5mpg over 22.4mi

I agree that a higher SoC at highway speeds is best for MPG.

Wayne took along a SGII even though the FFH has the smart gauges. With the Nav system in my FEH I still have two SGIIs hooked up so I'm not switching from screen to screen to see what's going On. The percentage of SoC on the SGII is my most important gauge to me. Remember, we have CarlD here and you are driving a Ford. You know what I'm getting at....
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GaryG

@RLC: I will have to re-check the speed. I had thought it was in the 50-60 range, but I could be mistaken.

I just did a fill up, as the "low fuel" warning came on, and my wife was freaking out... I was on par for 595 miles, hopefully this tank will be better.

Can a moderator relocate this thread to the FFH in the Hybrid section? This would make it easier for Hybrid owners to find.

I agree that a higher SoC at highway speeds is best for MPG.

Wayne took along a SGII even though the FFH has the smart gauges. With the Nav system in my FEH I still have two SGIIs hooked up so I'm not switching from screen to screen to see what's going On. The percentage of SoC on the SGII is my most important gauge to me. Remember, we have CarlD here and you are driving a Ford. You know what I'm getting at....
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GaryG

And now my sister/brother-in-law have a 2011 Fusion Hybrid.....