Highway driving, 114+ km/h and sudden loss of fuel economy

[openair]

For 10 months now I've been commuting 160km round trip 5+ days a week. During, and even before, I noticed that if you keep the vehicle above 114km/h it no longer tries to cycle between charging and discharging the battery as it (and hybrids in general) do at lower speeds. After making this trip many many times over the past year it became evident that driving 114km/h was more efficient than driving 110 or even 100km/h for the above and below reasons.

 

At 100km/h the engine will consume between 6 and 8L/100k until the charge is high enough that the threshold allows some electric driving until it discharges enough that the cycle repeats. This has the following negatives: charge/discharge wear of the battery, the vehicle cannot predict rolling hills resulting in repeated circumstances where the engine is now consuming 12+L/100k as it is both climbing a hill with no electric assistance and charging the battery from the bottom of the hybrid window.

 

Keeping it above 114km/h sees the following behaviour and benefits: the engine now consumes between 6 to 8L/100k until the battery is charged to the top of the hybrid window. The engine continues to run afterwards consuming as little as 4L/100km and 5.4/100k average. Climbing those same hills has the engine consume up to 8L/100k with electric assistance instead of the 12+ above. This all results in less charging/discharging wear of the battery, less fuel consumed and less stress on the engine and rest of the powertrain.

 

That was my experience for 9 months. I would get daily trips, one way, of 3.2 to 3.8L/100km and 4.5 to 5kw consumed with the ac on. Or 4 to 4.5L/100km and with the heat and winter tires on at below 0c.

 

That was my experience 5+ days a week for 9 months. Then about three weeks ago I had an alignment, tire rotation and other maintenance and diagnostics done. Including resetting the battery management system. They claim not to have disconnected the 12v or reset anything to do with idle or fuel trimming yet for a week afterwards I saw trips of 6L/100km and 4.5 to 5kw for the same trips as above but even with no heat or ac.

 

So I pulled the 12V battery and went through letting it relearn it's idle strategy and what not and I sometimes get similar fuel economy to what I had previously and sometimes not.

 

When I don't the vehicle runs in a charging or warm up phase much longer than during those previous 9 months. The engine will consume 6-8l/100km randomly in the same locations of the rolling hills I use to see 4-5l/100km. I'll be driving down a very gradual slope and the fuel consumption will begin to drop near the top of the slope than jump back up when the slope and increased or remained the same.

 

I believe the reason for this is partly due to me not being as good at letting the vehicle relearn it's fuel trimmings as the tech who did it 9 months ago but also that both the age of the battery (I see 5.0 kws at best) and the reset of the battery management means that the battery is correcting it's state of charge more often and when it corrects the state of charge to below the top of the hybrid window the engine has to run longer to return it to this Ev later set state of charge. I know the system is constantly over estimating and correcting in a negative fashion as I can park the vehicle at 10% or 3 Ev km remaining and return to find the hybrid portion more than half depleted.

 

This, imo, is a significant weakness of the implementation of the charge maintaining Ev later mode if true. I couldn't care less if I end up with a few precent fewer Ev km or less charge in the hvb but using 15-30% more gas is huge.

 

Edit: TLDR: Ford did some updates and resets and did not follow the manual instructions related to allowing the vehicle to relearn it's idle and other fuel trimming strategies (evident by having to redo certain settings on the left lcd and touch screen and mfm trip data). I got the vehicle back from Ford and it was using nearly twice the gas for the same trips I'd been making daily for a year. I fixed this to within 15-30% of that and your videos fuel economy by pulling the 12v and letting the vehicle relearn as per the manual. I'm still concerned about that 30% so I made this post

Edited October 25, 2016 at 11:58 AM by openair

[My14Energi]

Ummm.....huh?

[rbort]

Its all about this, read and watch the videos you'll see what I mean:

 

http://fordcmaxenergiforum.com/topic/4401-how-to-get-better-gas-mileage-on-the-highway/

 

And here is a previous post to show you also that you can get close to 50mpg at 65mph.  Look at the MPG scale in the video.

 

http://fordcmaxenergiforum.com/topic/4340-2-liter-atkinson-singing-all-the-way-to-florida/

 

So its not the speed, its having the battery remain at +2% of the EV later charge setting.  Apples to apples, faster speed (114km/hr) vs (106km/hr) should yield a worse KM/L due to higher drag.

 

-=>Raja.

Edited October 24, 2016 at 11:19 PM by rbort

[My14Energi]

All that means little for me. My commute is 90 miles that includes 40 miles of highway driving with a 70mph speed limit and if your not going 75 you'll get run off the road by everyone else. I've tried to set my cc at 72 and i still become an obstacle. It seems some people just go crazy trying to crunch the numbers. I get in, push start and drive, and enjoy the car. I reliably get 20+ ev miles using a full 5.1-5.3 kwh and my calculated average is 43 mpg, and thats going atleast 75 and sometimes 80+mph to pass. I watched those videos and i find staring at numbers and fiddling with buttons a waste of time for a couple %, the distance gained from 13% to 15% is miniscule. Notice the % is bouncing up and down but the ev available miles went nowhere. Again, to me thats not enjoying the car by staring at numbers on a screen. I switched over to the Energi from a Lincoln MKS which averaged 19mpg, so 43mpg is more than acceptable to me. More of a concern to me is stuff like i used to be able to watch a dvd in THX 5.1 in the MKS and this crap Sony system doesnt do anything and sounds horrible. I'd gladly give up a few mpg if only able to get my THX 5.1 back!!!

Edited October 25, 2016 at 12:49 AM by My14Energi

[openair]

The videos are interesting but i use to get those kind of numbers (50mpg) without worrying about when i put it into Ev later.

 

I wouldn't be worrying about the numbers if they continued to fit the advertised fuel economy and the budget based on that when I got the vehicle. They no longer do and increasing my $3000-4000/year commute by 15-30% is worth thinking about. I drive 50k km a year. $1000/year can influence if and when i get a different vehicle

Edited October 25, 2016 at 12:14 AM by openair

[rbort]

 

 

if your not going 75 you'll get run off the road by everyone else

 

Don't believe that, its just an old wives tale.  I've been driving slower than traffic (not speeding any more) with my Cmax and nobody is running me off the road.  This is not Dukes of Hazard or anything like that.

 

 

 

It seems some people just go crazy trying to crunch the numbers. I get in, push start and drive, and enjoy the car. I reliably get 20+ ev miles using a full 5.1-5.3 kwh and my calculated average is 43 mpg, and thats going atleast 75 and sometimes 80+mph to pass.

 

Its all about what you want and what you want to get out of the car.  You can just drive and not worry about it and get what you get.  Or you can be more involved, and get more MPG.  Either way works, nothing wrong with just driving and taking what you get.  The only thing I say, just don't complain about it as many have, i.e. not getting the 43mpg the car was originally rated for because of driving like the people who you're saying are trying to run you off the road.  If you sit and watch people drive, you can see alot of wasted energy, flooring it to accelerate or pass, racing up to a red light and slamming on the brake at the last minute, etc.

 

 

 

I watched those videos and i find staring at numbers and fiddling with buttons a waste of time for a couple %, the distance gained from 13% to 15% is miniscule.

 

You missed the whole point there, watch the video again and listen to what is being said.  It has nothing to do with increased EV range.

 

-=>Raja.

[rbort]

 

 

I wouldn't be worrying about the numbers if they continued to fit the advertised fuel economy and the budget based on that when I got the vehicle.

 

There you go!  You're complaining about that already  ;)   If you were not worried about it then why make this post?  I tried to show you how to get more miles per gallon, and your fixated on what the car can learn or not learn from you by disconnecting the 12v battery.  Its not that, its all in the video how to do it.  That's all you need to understand, and if you got it in the past you just happened to get lucky as the condition for the car to excel in mpg happens by chance here and there, but if you know what condition you need to be in, you can make it happen alot more often, but to do that, you need to watch numbers and be more involved in the drive, not just sit back, relax and forget about everything.  

 

-=>Raja.

[openair]

I'm not fixated on anything. TLDR for op: Ford did some updates and resets and did not follow the manual instructions related to allowing the vehicle to relearn it's idle and other fuel trimming strategies (evident by having to redo certain settings on the left lcd and touch screen and mfm trip data). I got the vehicle back from Ford and it was using nearly twice the gas for the same trips I'd been making daily for a year. I fixed this to within 15-30% of that and your videos fuel economy by pulling the 12v and letting the vehicle relearn as per the manual. I'm still concerned about that 30% so I made this post. That part about the numbers was in reply to my14energi.

 

Edit: I followed rborts advise and set it to Ev later at 95%. Got the same 15% worse fuel economy then before Ford had my vehicle that I've been getting.

Edited October 25, 2016 at 11:03 AM by openair

[My14Energi]

Ok, sorry....im not literally getting run off the road. But have semi's on your a$$ and passing to swerve back in front isnt very fun. Nor dump trucks, pickups or woman driving stupid in their cars. Its something called the average flow of traffic, regardless of speed limit, and if your under that average flow your actually a bigger danger than the people going 80mph. Highly annoying to be "that guy" causing everyone to drive around you. Our own state troopers have warned of driving below the flow of traffic. They did a whole campaign where they ticketed drivers for going too slow, too slow being over 10mph under the limit. But they recognize that a 70mph limit results in a flow of 75. I run by troopers daily running radar doing 75. You want to be that guy thats your choice. Always one in every crowd. I also dont put an ounce of effort to notice people "wasting energy". What you do is your business, doesnt bother me a bit.

 

As i stated before you wont hear me complain about my actual 43mpg. Dont care what Ford stated, didnt buy it based on what Ford said it would do. Im perfectly satisfied going from a 19mpg car to 43mpg.

 

What i saw in the video is "charging" the HVB while driving. Charging at a level that is insignificant to experience any noticable benefit, to me anyways.

 

Also that video is a CMax which is an egg of a car. The Fusion being a completely different shape and size car would surely drive and behave completely different thus different expectations. If im not mistaking there is a slight weight difference between the Fusion and the egg.

 

Bottomline....100% satisfied (minus sound system) owner of a top of the line Fusion Energi.

Edited October 25, 2016 at 02:22 AM by My14Energi

[My14Energi]

I'm not fixated on anything. TLDR for op: Ford did some updates and resets and did not follow the manual instructions related to allowing the vehicle to relearn it's idle and other fuel trimming strategies (evident by having to redo certain settings on the left lcd and touch screen and mfm). I got the vehicle back from Ford and it was using nearly twice the gas for the same trips I'd been making daily for a year. I fixed this to within 15-30% of that and your videos fuel economy by pulling the 12v and letting the vehicle relearn as per the manual. I'm still concerned about that 30% so I made this post. That part about the numbers was in reply to my14energi.

Understood. I'd be slightly irritated too if i got less performance after the dealer serviced my car.

[My14Energi]

 

This was the numbers from my commute this morning. Again...roughly 21miles @ 75mph and 23miles @ 45mph. Thats the result. Totally satisfying on my end.

 

My point with all this is my time is worth more to me, enjoying my drive, than the gains achieved by fiddling around like the car is a video game with buttons and arrows going up and down. By my calculations, granting the magic number of 50mpg, a gain of 5% battery equals about 1 mile of driving. At 50mpg one mile costs about 5 cents. If staring at a screen and pushing buttons is worth 5 cents to you then thats fine, but thats not for me.

[openair]

Yes, my14energi. That is nice fuel economy. Better than i use to get before Ford got my vehicle. Much much better than I get now. If i had continued to get those numbers I would never have made this thread.

[My14Energi]

Yes, my14energi. That is nice fuel economy. Better than i use to get before Ford got my vehicle. Much much better than I get now. If i had continued to get those numbers I would never have made this thread.

So aside from the alignment and rotation what else were you experiencing to have them service the car? Im sure alignment and rotation wont have any effect on the performance, but these cars are so dependant on the computers and programming that i could see that having an effect. Just wondering what prompted them to mess around with the electronics

[openair]

Go times were using tomorrow schedule instead of today's. Excessive moisture inside the vehicle every morning. They reset the battery management system and a few other modules and preformed the Tsb related to moisture updating the fcim and whatnot.

 

The go times issue remained afterwards and was fixed when i pulled the 12V. The moisture issue is fixed.

Edited October 25, 2016 at 02:03 PM by openair

[flyingcheesehead]

Openair,

 

What was the temperature outside when you made the previous measurements? How does it compare to the temperature when you made the latest measurements? How are you taking your measurements (the L/100km ones)?

[openair]

I stated both winter and summer numbers in the op. I was getting better fuel economy 4 weeks ago with the ac on at 26c than two weeks ago with the ac off at ambients of 21c to 24c(75f). The trip meters and instantaneous fuel guage.

 

I checked the air pressure of the tires yesterday afternoon though. They were below the factory recommended 35psi. When they did the rotation they most have bled them from where i had them slightly over pressure. My fuel economy seems to be improving again.

Edited October 27, 2016 at 12:39 AM by openair

[openair]

I got better fuel economy this morning at 0c with the heat on than two weeks ago at 20c with no climate controls on. Under inflating the tires and not allowing the vehicle to relearn it's idle and other strategies after resetting it definitely has a big impact on fuel economy.

[cwstnsko]

Checking the tire pressure is a good call, there is also a possibility that the car originally came with it's alignment optimized for fuel economy and they aligned to more "normal" settings.  Typically cars that are trying to optimize for fuel economy will have less toe-in than "normal" settings.  This decreases the rolling resistance of the car, but can make it feel like it wanders a bit at highway speeds.  More toe in can feel more stable with stronger self centering and straighter tracking.

 

All of the cars I have purchased in recent years have been MPG leaders in their category, and they all have had a bit more "wandering" due to having the alignment set to lees toe-in.

[openair]

You're probably right. I was unaware of this. I bet it didn't even need an alignment.

[openair]

Place that did the alignment says they put the serial number in their computer and do what it tells them and that it wouldn't have much affect on the fuel economy but looking at the front end you can see the tires are obviously toed in. If i see can it with the naked eye than it is probably more toed in than it should be.

 

Went to a different place for a safety today. They wouldn't pass it due to some new Ontario rules that the brake pads must make 75% unrusted contact with the rotors. They say the rotors are more 50% than rusted. They also say it is out of alignment and another look at the numbers they gave me show the toe for the front at 0.21 degrees and the rear at 0.25 degrees which is outside the 0.20 degrees I've seen as proper numbers.

 

The dealership that did a works inspection two weeks ago says the rust is not really a safety concern and simply noting that the rotors were slightly rusty is sufficient. They say these new safety rules are designed to protect used car buyers and not a safety thing per say. Going to get them to look at the alignment again.

 

Idk what to believe about that. Anyone able to confirm what the alignment numbers should be?

Edited October 28, 2016 at 10:06 PM by openair

[openair]

Despite summer weather and all the things I thought had fixed it I continue to get very poor fuel economy intermittently. My average was 3.8L/100k and 4.5kw. I've seen as poor as 7.1L/100km and 4.5kw. Often I would recently get 5.5-6l/100km and 4.5kw. Then my charging cable died. So for two weeks I drove without charging. I often got 5.5L/100km and 0kw. This is all for the same 79km each way commute.

 

It seems the vehicle may be running in a warm up or charge phase for much longer than previously. 20+ minutes at 114kph.

I've noticed that accelerating to 130kph for a short period seems to reduce the length of the warm up phase and then keeping it between 118-122/kph, depending on climate demand, I can get the 3.8L/100kms again.

 

This leads me to believe one of three things: the transmission is dieing and or needs a fluid change. The fuel trimmings have been corrupted and the 12v should be pulled (The go time issues I also intermittently experience, that can be fixed by disconnecting the 12v, seems like another symptom of similar corruption). One or more temperature sensor is giving bad numbers. Or the engine and or motor control module is dieing or similarly corrupted.

 

I'm going to finally buy a real odb2 for this because I'm getting no where with Ford.

Edited June 23, 2017 at 10:54 PM by openair