I AM NOT going to adopt the new FE improvements

[HannahWCU]

Two scenarios for driving a distance on a flat road:

 

1) Currently, you drive above the current EV threshold to charge your batteries - essentially overriding programmed behavior. A few miles down the road, (call this "point B") you have a relatively charged battery.

 

2) In the post August Update scenario, you can't assume ICE at 65MPH. You imagine that you will actually see EV at 65, until the battery level drops below it's charging threshold (a few miles down the road at point B).

 

So under scenario 1, you are a few miles down the road at point B with a relatively well-charged battery.  Under scenario 2 you are reach point B, with a relatively weak battery. 

 

The thing to consider is that you have traveled to get to point B.  Under scenario 1, you got to point B under ICE. You have more charge in your battery, but less fuel in your tank. Under scenario 2, you got to point B under EV. You have less charge in your battery. but more fuel in your tank.

 

Let's next move beyond point B to travel a few miles further (call this "point C"), taking into consideration the relative state of batteries. Under scenario 1, you will travel from point B to point C under EV, and arrive at point C with a relatively depleted battery. Under scenario 2, you will travel from point B to point C under ICE, and arrive with a relatively charged battery. 

 

If all things were equal, (a closed system), then on a flat road, I might suggest that you will not realize gain or loss in FE performance due to a change in the EV threshold. Results might be different where the terrain changes (hills, etc.) .

 

I might be missing a lot of things, and just putting this out there as a point of discussion.        

 

I can't speak to this 100% accurately because, as I have stated, there are very few “flat” roads in my area to test this.  These scenarios assume that, on a flat road and with the CURRENT software and traveling above 62 mph, that most of the time you are using ICE and charging the battery.  The second assumption is that with the NEW software, on a flat road traveling at speeds up to 85mph, you will be in EV and discharging the battery.

 

However, in my limited experience (with flat roads), it isn’t as black and white as these scenarios make it out to be.  At any speed (up to the current limit of 62mph) I can be in EV and using the battery OR I can give it a little more pedal, trip the car into ICE and then back off to maintain the same speed.  Only now I am charging.  Also, when the battery is fairly charged (say above 70%), the CMax uses the battery to supplement the ICE at speeds above 62mph.  Again, this is my experience, with the terrain I drive on every day.

 

I am also betting that it will be MUCH harder to keep the car in ICE as speed increases.  The wind resistance will be MUCH greater at 70 than 60.  I would not be surprised if it would be almost impossible to keep the CMax in ICE at constant speeds above 70.

 

Yes, I know the next comment will be “How does the Energi get to 85 with the same drivetrain (except a bigger battery)?”  I am guessing that the Hybrid model limits current to the electric motor more than the Energi does. Have you ever tried to get the CMax Hybrid to 60MPH in pure electric?  Want to bet the Energi does it faster? Why would that be, they have the same drivetrain, UNLESS the Hybrid limits current to the motor to preserve what little KW it has.

 

I expect some people will get worse mileage with the new software, but I am betting that the vast majority of normal drivers of the CMax will get better mileage with the update (maybe not on this board, I don’t think too many of us consider ourselves “normal” drivers :) ). 

 

These are just my thoughts on the new software. Comments are welcome, just trying to add to the discussion.

[plus 3 golfer]

What we can hope for is that Ford can now better optimize the overall efficiency of the C-Max by allowing EV operation up to 85 mph. Here's a link to a very good slide presentation on  power split transmissions.  As slide 33 says: 

 

Engine and electric system matching are essential to realize geographical preferences in the market 

– The power split device & the electric machine CPSR

– constant power speed ratio are key elements in this strategy

 

The consumer preference apparently is for better high speed FE.  I would expect the efficiency map on slide 33 showing both ICE and the motor/generators would be representative of the C-Max.  I would guess that most drivers do not drive on a perfectly flat road.  There are bridge over / under passes, slight changes in elevation and so forth and thus changes in torque / power requirements.  By allowing the traction motor to assist more one can better optimize efficiency.  For example, one can be going up / down a slight hill at say 75 mph where if ICE were to supply virtually all the power, the engine rpm may fall outside its most efficiency operating area.  By allow the traction motor on uphills to assist to a greater degree or by having battery storage capacity now available to run the generator to store energy (since more traction motor use at higher speeds will drain the battery), ICE can now likely run in its most efficient operating area more of the time than with the 62 mph restriction.

 

Obviously, the control strategy Ford chooses could hurt some drivers depending on their unique driving situation but I believe for cruising the interstates and freeways at 65+ mph this control strategy (along with enhanced, optimized grille shutter operation) should improve cruising FE for most drivers.  I also wouldn't expect this "cruising" control strategy change to not affect FE below 62 mph.

 

I know there are those concerned about the "high" ICE mode - negative split mode where the battery is near fully charged (virtually no room to store additional energy) where FE is higher.  This generally requires a slight downhill grade.  This higher FE is because the control strategy is keeping ICE in its efficient operating area.  But to do this, the generator use energy to reduce engine rpm to operate the engine to maintain high torque, low speed at its most efficient operating points. Using the generator to reduce engine rpm in the negative split mode likely uses less energy than the energy lost by ICE had ICE moved out of it's most efficient operating area. The "freeing up" of the 62 mph restriction and allowing the electric motor full EV mode up to 85 mph, should provide more opportunity during higher speed driving to better use the HEV system. (

 

These are my thought and time will tell.  I eagerly await the update. :)

[HannahWCU]

What we can hope for is that Ford can now better optimize the overall efficiency of the C-Max by allowing EV operation up to 85 mph. Here's a link to a very good slide presentation on  power split transmissions.  

 

Thanks for the link!!

 

These are my thought and time will tell.  I eagerly await the update. :)

 

Thanks for adding to the discussion!

[SnowStorm]

Yes, I know the next comment will be “How does the Energi get to 85 with the same drivetrain (except a bigger battery)?”  I am guessing that the Hybrid model limits current to the electric motor more than the Energi does. Have you ever tried to get the CMax Hybrid to 60MPH in pure electric?  Want to bet the Energi does it faster? Why would that be, they have the same drivetrain, UNLESS the Hybrid limits current to the motor to preserve what little KW it has.

Quite sure you are right about the battery limiting the available current (and hence the power).  A given battery not only has a kw-hour rating but also a maximum instantaneous power and current rating that scales with the kWh rating.  The Energi battery is 7.6 kWh versus 1.4 so it can, I would expect, put out at least 5 times the power.  Its not just an issue of how fast it gets drained.  With 5 times the power you can go faster and accelerate faster, not just go further.  The inverter is no doubt smaller too by the same ratio (saving cost).

[Jus-A-CMax]

Energi has a different gear ratio which helps with the battery. I hope the rumor is right that Ford may unleash a wee bit more battery juice. I know its there as I was driving home, EV+ kicked in but I was down to 1/3 and lo-n-behold I had such a high EV threshold, almost up 3 bars. Woah.

[ScubaDadMiami]

I think that Riddley is getting at it.  In a lot of ways, it may not make much difference for numbers.  However, I think that these changes will enhance the performance of the car for the driver, making the experience better, and the car easier to drive.  For some styles of driving, there will also be bigger FE improvements.  My guess is that this will happen for people that are "just driving."

[salsaguy]

scuba, that's the idea.if Ford wants to get a larger share of the hybrid market and try to take away the prize belt from the Prius, they need to make it fun to drive, easy to drive, nicer to drive, and deliver the numbers (close to/equal to/better than the Prius) for the larger population of common drivers and not cater to the niche market of hypermilers that most prius owners have become. hopefully the FE update will make a lot of folks smile when driving the cmax and make the buying decision a no brainer.

and let's hope the negative mpg press of the past hasn't hurt the cmax and Ford too much already.

[ScubaDadMiami]

Agreed. 

[Jmonty]

I'd go get it today but my dealer service department had no idea about the update still.

[darrelld]

the problem is that if none of the users here on the forum do the update none of us will know how it works and if it's better or not.we need someone with a good baseline and steady routes so they can compare apples to apples.

we can't just let the non forum users get it and be in the dark.

Ok, you talked me into it. I will line up to be one of the first to upgrade. My wife drives the same 30 round trip to work everyday so I have a baseline to reference from the update event. We have noticed a big hit in FE with the 99 degree temps of late, AC was mentioned as a point of the updates optimization.

Edited July 23, 2013 by darrelld

[Jus-A-CMax]

Go darrelld!!! :rockon:

[salsaguy]

Darrell, glad to hear you changed your mind about the update. i think there will be more good than bad that can happen for you.

[ScubaDadMiami]

We have noticed a big hit in FE with the 99 degree temps of late, AC was mentioned as a point of the updates optimization.

I know that I will be awaiting your report.  I hope that there will be AC FE improvement.  I use AC all the time, all year long.  I'll never get the truly big numbers of our record holders, but I would like to be able to get 50 mpg or so, consistently. 

 

I am starting to consider plans for my first big road trip, maybe to Western North Carolina mountains.  If I go in September, I hope to have the upgrade done before departure.  It would be great to hear about it from someone, before I make that upgrade and do all that driving.

[HannahWCU]

I am starting to consider plans for my first big road trip, maybe to Western North Carolina mountains.  If I go in September, I hope to have the upgrade done before departure.  It would be great to hear about it from someone, before I make that upgrade and do all that driving.

 

You'll have fun with all those mountains and hills.  Like a roller coaster, the uphill sucks, but the downhill makes it all worth it!!  :shift: