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Best Engine RPM for minimal FE loss.


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But the last thing I need is another display to look at instead of traffic! That's why I'm not looking for a smart phone holder, as I've seen some folks do, and hoping I can log the data and review offline.

 

Then again, I drove my high-MPG rural route today with the middle grill blocked, but without cycling heat, and hit 30.0... I could barely get 1/3 of my mileage in EV, vs. 2/3 in warm weather. Highway nets me 33-38 at these temps.

 

Have fun,

Frank

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Each segment starts with a full EV battery so I also calculate a "hybrid-mode"(HM) MPG by subtracting an estimate of 40 miles driven in pure EV mode.  Two bikes on the back also contribute to mileage in some fashion.

 

Wait a minute. You're getting 40 miles pure EV out of your Energi? I was gonna get one but my dealership isn't EV certified yet so we don't sell them but, they're rated at 21 miles EV and I thought best average was around 26 miles. How are you driving / what speed etc. to get this type of range? Just curious.

 

Thanks

 

John

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Wait a minute. You're getting 40 miles pure EV out of your Energi? I was gonna get one but my dealership isn't EV certified yet so we don't sell them but, they're rated at 21 miles EV and I thought best average was around 26 miles. How are you driving / what speed etc. to get this type of range? Just curious.

 

I wish!  But no, that's 20 for each leg of the trip, with a full charge starting each leg.  My best EV miles in local driving before the ICE started is 25.2, 25.8 and 26.8 so far.  Many times it also looked like it would have been above 24 but I arrived at home before the ICE started.  Thread on this: http://fordcmaxenergiforum.com/topic/1965-268-miles-before-the-ice-started-new-personal-record/?do=findComment&comment=16221

Edited by ArizonaEnergi
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I live in East Tennessee and we've got a lot of hills around here. (putting it mildly)

Much respect to those mountains.  In September, I was in the mountains of western North Carolina.  (Here is the trip report.)  At the time, my C-MAX only had about 4,000 miles on it, and I was getting around 48MPG while in the mountains, running the air conditioner.

 

You are absolutely right; there is no one way to drive for best FE in all conditions.  This kind of thing appeals to my nature.

 

I earn part of my livelihood as an instructor for a piece of underwater scuba equipment that is also highly technical.  I tell my students that this piece of equipment is "the thinking diver's" rig.  Sure, you can just go with autopilot and have a lot of fun.  However, if you fly it manually, and you put thought into operating it manually, you get the best efficiency.  It takes a little more work, but by practicing all the time, it becomes second nature, and isn't that big of a deal to do. 

 

The C-MAX is the same.  You learn to develop awareness of road conditions, which allows you to drive in the best way for safety and efficiency. 

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  • 3 weeks later...

lol, I dunno either...

 

Hey SDM, remember my ole "My 2c: EV" thread...we talked about 1 bar and 2 bar. I didn't check the tachy either but lately I've been flipping between the EMPOWER and the MyView where I set the tachy. I noted that it all depends on the road and speed, a 2 bar could be 2K rpm or 3K rpm. My rule of thumb now - as I sit mostly with the EMPOWER, is about 1 3/4 bar burn after my 15mph EV start...that gives me 2K rpm. Its all relative. Somehow for me...at the end of the day....I still prefer the 2 bar (or 2.1 bar) straight burn as the sweet spot for the decent acceleration & charging...but lack the scangauge to prove this.

 

I don't know how much the scangauge costs, $100-$200, but for $14 ($9=OBDii $5=Torque) you can have a far more advanced interface, "Torque" for both iphone and android I believe, measures and displays about a zillion (well, maybe 100 or so) data points. Highly recommended. 

 

Speaking of which, I've found that Torque is about 10% ... optimistic. That is, when the C-max displays 40mpg on the instant mpg bar, Torque will display about 44mpg. 

 

Now, the good news is; even if it is not accurate to the tenths, it is still useful in that it indicates peak efficiency, if not entirely accurately, and this also explains the disparity when others have tried to replicate my 75mph peak efficiency claim, and have not seen the same 45mpg-60mpg.

 

I've been keeping an eye on the instant mpg readout, and while EV up to 15mph then a measured acceleration- sub-2000 rpms being the benchmark discussed in this thread as the easiest benchmark of peak efficiency, but the instant mpg seems to indicate that your previous finding of 2-2.1 bars is MORE efficient, (which makes a lot of sense really, the engineers would most likely have put the bars at the best efficiency points) as the instant mpg CLIMBS with speed when accelerating slightly more aggressively than the 2000rpm, which results in a really sloooow build to speed and then cruise (which FEELS ECO, but the instant mpg indicates is not the most efficient), which makes sense when you realize the CVT is able to adjust to higher gearing, which means less load, which means better mpg. 

 

As has been noted many times over on the net, there is no "the" best way to drive to achieve best mpg, there are too many factors changing second by second to ever truly master all of them all at once, uphilll/downhill, traffic, temperature, weight of passengers/items/gas, wind, battery level, etc., so having that instant feedback is crucial, which is either really sloppy of Ford to have not given this tool to those in hybrids trying to maximize and game-ify their driving, or a masterstroke of publicity strategy, i.e., speedos are mis-calibrated to show 2-3mph MORE than actual, causing drivers to drive slower than speed limit, at less than peak efficiency, months pass while C-max STILL outsells Prius even WITHOUT equaling or surpassing its mpg, and becomes known as a better car in terms of style, comfort, ride, technology, etc., THEN, BLAMMO, SHOCKING NEWS, the C-max has been MORE efficient than Prius all along, but a simple error in the display made it seem as if it weren't!

Edited by MacGyver
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Here is something I have been working on but have yet to find a consistant method with my CMax. When climbing a hill, one of the techniques recommended for my sons 2004 Honda Insight is to punch the throttle for as long as possible (speed, traffic etc.) in order to engage both EV and ICE. It works very well in his Insight but, as I said, I have yet to find a method to engage both manually with my CMax. Sometimes it works, other times no joy.

 

Thoughts?

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C-Max does this automatically.  Do you have the charge/discharge arrows turned on?

Yep. I have noticed it happen on occasion and it appears to be dependent on battery charge. The Insight does it automatically under certain circumstances as well but you can work the system to kick it on manually.

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Depending on the steepness and distance, I typically make a 2 Bar burn for this type of thing.  If it is really steep but not too long, I can go as high as 3. 

On a steep grade, the Insight will burn less fuel during the climb even though the RPMs are higher due to the EV assisting. The instant MPG rate will show poor milage, but the overall MPG will climb. While the milage appears poor for a short period of time, the shorter burn duration uses less because of the EV assist. Wanted to see if the CMax would respond the same way.

Edited by BretJ
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On a steep grade, the Insight will burn less fuel during the climb even though the RPMs were higher due to the EV assisting. The instant MPG rate will show poor milage, but the overall MPG will climb. While the milage appears poor for a short period of time, there is a "happy spot" where the shorter burn duration uses less because of the EV assist. Wanted to see if the CMax would respond the same way.

 

I might add that the Insight hypermilers recommend full acceleration from a start in order to get the EV to kick in. Again, as traffic and speed limits allow.

Edited by BretJ
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That may be the case with the Insight but the CMax EV motor & battery pack is far more powerful than the Insight, I would suspect. For us Maxers, EV start is recommended as the CMax is a very heavy car and why burn gas to put momentum into it from stationary. Also, from 0 to 10 mph, the EV has more than enough power to keep up with the regular traffic and then kick in the ICE to power on....

Edited by Jus-A-CMax
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On a steep grade, the Insight will burn less fuel during the climb even though the RPMs are higher due to the EV assisting. The instant MPG rate will show poor milage, but the overall MPG will climb. While the milage appears poor for a short period of time, the shorter burn duration uses less because of the EV assist. Wanted to see if the CMax would respond the same way.

Interesting behavior. I only drove a Honda hybrid once and didn't have much chance to play with it. It was an early Accord hybrid and it was more about power than economy.

 

My impression of Honda hybrids is that their systems achieved through finessing and fine tuning what Toyota did through high technology. Except that Toyota has a high degree of finesse as well and Honda couldn't achieve the same high mileage AND low emissions. Even the C-Max is behind Toyota in that repect but it is because Ford also prioritized the driving properties and "feel" of the car.

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  • 2 weeks later...

Any of you guys that have myFord Touch, have you ever noticed on the Hybrid Information Screen, the following behavior? As you know it will show what the drive system of the car is doing and why. The other day I noticed, while in the midst of a 2 Bar Burn, that when the load indicator on the Empower screen reaches 2 bars, the status of the Hybrid Info Screen goes from "Charging HV Battery" to "Hybrid Drive"

 

Now I know this doesn't seem like anything out of the ordinary except, over on the left screen the battery meter continues to show a chevron above it, indicating that the vehicle is in a state of charge, furthermore if I switch to the Engage screen, it shows no assist by the battery. I have observed this on every occasion since first discovering it, so it doesn't seem to been an oddball occurrence.

 

Could this just be a fluke in programming, or is the car actually giving assist and not reporting it in the standard information screens, and could this be why JUS and others feel that it will get better FE at 2.1 bars? Because the battery is actually taking some of the load off.

 

Just my observation. Anyone feel free to chime in. :)

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Any of you guys that have myFord Touch, have you ever noticed on the Hybrid Information Screen, the following behavior? As you know it will show what the drive system of the car is doing and why. The other day I noticed, while in the midst of a 2 Bar Burn, that when the load indicator on the Empower screen reaches 2 bars, the status of the Hybrid Info Screen goes from "Charging HV Battery" to "Hybrid Drive"

 

Now I know this doesn't seem like anything out of the ordinary except, over on the left screen the battery meter continues to show a chevron above it, indicating that the vehicle is in a state of charge, furthermore if I switch to the Engage screen, it shows no assist by the battery. I have observed this on every occasion since first discovering it, so it doesn't seem to been an oddball occurrence.

 

Could this just be a fluke in programming, or is the car actually giving assist and not reporting it in the standard information screens, and could this be why JUS and others feel that it will get better FE at 2.1 bars? Because the battery is actually taking some of the load off.

 

Just my observation. Anyone feel free to chime in. :)

I was able to observe this phenomenon on my drive home yesterday. In the Engage display. Someone with additional instrumentation would need to report what high-voltage battery current flows are occurring. I have a sneaking suspicion we are seeing something like a toggle between plus zero and minus zero. This is contradicted by the fact that the up chevron remains. I will use the following term despite my limited ability to comprehend it: Negative power split mode. I suspect we are seeing constant charging with a toggle to hybrid drive while charging continues. The quantity of drive assist is so small that it doesn't register on the blue EV bar.

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I was able to observe this phenomenon on my drive home yesterday. In the Engage display. Someone with additional instrumentation would need to report what high-voltage battery current flows are occurring. I have a sneaking suspicion we are seeing something like a toggle between plus zero and minus zero. This is contradicted by the fact that the up chevron remains. I will use the following term despite my limited ability to comprehend it: Negative power split mode. I suspect we are seeing constant charging with a toggle to hybrid drive while charging continues. The quantity of drive assist is so small that it doesn't register on the blue EV bar.

Said much better than I ever could have. +1 Either a toggle or some kind of simultaneous split.

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I took some video of this yesterday. Normally, I never have the main screen showing the vehicle. (I usually either just leave MFT on the Home screen, or I change it to show Map). So, I never saw the changes on the main screen until then.

 

The screen shows three states: Charging Battery, Hybrid Drive and Electric Drive.  During Hybrid Drive, on the Empower screen, you can see ICE/EV both on in the bar graph, and you can see the battery switching back and forth between ^ and - (I can't find an arrow down key on my keyboard). You can also see that the instant MPG graph is moving between about 45-57 MPG, depending upon the split between positive and negative arrows on the battery.

 

I am guessing that we can't load video to this site, and I have never loaded video onto the Internet. So, if somebody wants to tell me a non-laborious method to do so, I'll give it a try, if anybody is interested in seeing the clip. The quality is not the greatest, and unless I can find a way to rotate the frame (because I had to hold the phone sideways to take the video), you'll get a little bit of a stiff neck checking it out. Nonetheless, it shows the whole story.

Edited by ScubaDadMiami
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Okay, here is the link. Again, I apologize for the camera work.

 

You can see the ICE/EV split on the left screen and the Hybrid Drive status on the main screen. On the right screen, you will see the gauge showing that ICE is on but fuel economy is just under 60 MPG at 54 MPH.  On the battery status, you will see the battery nearly topped off, and you will see the arrow up and arrow down on it.

 

Unfortunately, I wasn't able to catch the moment when the arrow switches, but when the split is going for long stretches, it goes back and forth between up and down. That is the sweet spot to consistently get best highway FE.

Edited by ScubaDadMiami
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Okay, here is the link. Again, I apologize for the camera work.

 

You can see the ICE/EV split on the left screen and the Hybrid Drive status on the main screen. On the right screen, you will see the gauge showing that ICE is on but fuel economy is just under 60 MPG at 54 MPH.  On the battery status, you will see the battery nearly topped off, and you will see the arrow up and arrow down on it.

 

Unfortunately, I wasn't able to catch the moment when the arrow switches, but when the split is going for long stretches, it goes back and forth between up and down. That is the sweet spot to consistently get best highway FE.

I'm glad you didn't get hurt doing that video. How long did you go before ICE had to start charging again? 80 degrees is about the prefect temp and I don't think it gets much better at high temps. :)

 

Paul

Edited by ptjones
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I'm glad you didn't get hurt doing that video. How long did you go before ICE had to start charging again? 80 degrees is about the prefect temp and I don't think it gets much better at high temps. :)

 

Paul

The only real issue seems to be in finding a long stretch of flat road. While South Florida is flat, I-95 has many overpasses built in for local traffic crossings.

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  • 3 weeks later...

Guys I'm finding that two bar burn is a great way to keep up your efficiency when you need to accelerate but I still believe that a 2000 RPM burn is the best way to keep up your efficiency when you're going up a hill or even as you're just moving along.

 

Accelerating is really the only thing that I find a two bar burn good for. Then again around here we have a lot of hills, it's not like other places where it's mostly flat. I don't recommend it up an extremely steep hill because you will get very very very slow.

 

Loving the warm weather lately. However I wish mother nature would make up her mind. Will have a day or two in the 60s low 70s and then it'll drop down the 40 or 30. With the warmer weather I'm in getting 55 to 59 miles per gallon on my way home and we haven't even got into the mid 70s or even the 80s yet.

 

Was getting mid to high 40s at best 51-52 mpg and those were only when it was in the 40s going home.

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  • 1 month later...

Okay, so I used to drive a Civic Hybrid, and adjusting to this car has been a little bit of a challenge, (Operates completely different) however I love my Cmax! I've seen a lot of discussion about a 1 bar burn vs a 2 bar burn, and while charging and power is better on a 2 bar burn, I don't think it is the most efficient method.

 

Something I learned with my Civic is that keeping the ICE at or below 2,000 RPM kept my efficiency up. Although the Cmax doesn't have a prominent tachometer, it can be selected in "My View". I'm finding that I have minimal FE loss when I do not allow it to go over 2000 RPM. Not great up hills, I sometimes get down to 25 mph and would never attempt it on a 2 lane highway or interstate, but gain great speed on the way down. On flat groud I find that the longer you burn at 2000 RPM the more speed you gain and often time will get up to 65-70 and a 90% battery and 55-65 instantaneous FE before dropping back in to EV mode.

 

So this is basically how I roll. I use Empower and run EV until my threshold falls below one bar and then switch to my view and maintain a 2000 RPM burn until my battery is up and it switches to EV assist or I come to a "decent" downward run. As the battery charges the engine RPMs will slowly drop below 2000.

 

After filling up the other day I ended my trip at 59.8 mpg for 27 miles, my tank is now at 49.3. It would be much higher if it wasn't for the short runs to the store over the weekend, short trips kill FE.

 

Anyway, I would like to get other drivers input on this or if anyone else has tried it, what they think.

I live in a rural county and most of my driving is done on 50 mph or less highways.  The method described by John Sparks works well for me.

 

 I often drive 20.1 miles from my house to Costco/Trader Joe's.  Last summer, a good result there and back would have been in the low 50s mpg.  Last Wednesday, using this method I got 58.8 mpg from my house to Trader Joe's and an amazing 61.8 mpg coming home.  This route is up and down hills, and I sometimes used 2 bars on the Empower screen to maintain the speed limit.  The big difference for me is that I am much more likely to intentionally stay in ICE if running at 2000 rpm or lower.  Before reading Mr. Sparks post, I would try to be in EV mode as much as possible.  Now I am driving more aggressively (faster) and getting better mpg.

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