gultim

Can anyone share contact information regarding any Engineers at Ford who work on the C-Max Hybrid Power Train? I would like to ask them about my unusually low engine loading at highway speeds and why my car's engine is not being lugged down by going into negative split mode to optimize MPGs. Thanks!

About a half an hour prior to taking the 3 pictures, I descended a mile long 10% grade hill and use the down hill decent control (which is a fantastic feature). I left the down hill decent control on as it makes no difference either way in my car. Maybe that is a clue? When driving on the flats, do you notice lower engine revs when you turn off this feature and higher revs when turned on? I know I read something in the manual last year pertaining to it and tried many times since to see if there was a difference in engine rpms but never witnessed any RPM or MPG changes after selecting either mode. To me, this button only does one thing and that's limit the speed going down a hill.

Yes, that sounds correct. I am not experiencing the necessary load on my engine. Regarding Ford's "Preliminary 2013 MY OBD System Operation Summary for Plug In and Hybrid Electric Vehicles" it states that our C-Max's should enter negative split mode under certain conditions. Other publications have explained negative split in the following manner: "§ 1.3.5 Negative split mode - In this mode the power in the transmission flows the other way around. The electric motor delivers power via the generator and the planetary gear set to the engine. This is done to keep the engine running at low speeds and thereby optimizes the fuel economy." Another described it as follows " Negative split mode – Forced engine lugging to optimize fuel economy" I also found LOAD explained as follows: "You want to maximize the amount of load on the engine at the lowest RPM, so a higher load at lower RPM is better than lower load at higher RPM. It is more fuel efficient to have more load at lower RPM than at a higher RPM, as you are getting more bang for the buck at that point.” A driver from the Ford Fusion Hybrid Forum stated the following about his car: “The car often shows 95-99% LOAD when accelerating slightly more aggressively such as accelerating onto the freeway, when accelerating in the city it often shows only 80-85%.” I believe the C-Max has the same Hybrid Drivetrain as the Fusion. It appears that my C-Max is never entering the negative split mode. The attached 3 pictures show the engine load, which was captured today on that ideal flat stretch of highway I described earlier in this post. My Engine LOAD was 66%. It looks like it should be around 85% (Prius LOAD is 82 to 83%). In order to raise this LOAD percentage, I need my car to lug its' motor RPMs down by entering the negative split mode. For those of you with the ability to measure engine LOAD and Hybrid Battery AMPS, what is your engine LOAD around 0 AMPS on the flats at 60 MPH and no wind? Also, since the C-Max can do 85 MPH in electric, I think that translates to 10,000 to 12,000 RPM that both the motor and generator can safely operate at. At this speed, negative split can be entered at very high driving speeds...much higher than what this link indicates http://eahart.com/prius/psd/ as that older eCVT drivetrain was based on the first Generation Prius. Please share your engine LOAD pictures. Thanks in advance :yahoo:

If it has to do with physics, and if it was designed by humans, then it can be substantiated with math...that is how Engineering works. And, if you understand engine fuel consumption at different horse powers, horse power needed to maintain a specific vehicle speed, and distance traveled, then you can calculate the energy needed to propel that vehicle at a given speed over a specific distance. It is undisputable and industry known that to achieve the best MPGs you need to operate a gasoline engine at it's lowest RPM while producing enough horse power to maintain the vehicle at the desired speed which then will reveal the quantity of fuel consumed. Again, all this can be calculated. Toyota has figured this out. My testing using a Scan Gauge II revealed that their engine revs at 1,200 rpm at 45 MPH and achieves 75 MPG, at 55 MPH it revs at 1,400 RPM and achieves 65 MPG, and at 65 MPH the engine revs at 1,600 RPM and achieves 55 MPG. My C-Max revs at 2,000 RPM at 65 MPH under the same driving conditions as the Prius and achieves only 40 MPG. If I set the C-Max transmission to Low then the engine revs to 4,400 RPM and the car achieves 25 MPG. Yes, the Prius has a better C/D and is lighter. I bet that if you add parts to the Prius body to lower its' C/D to that of the C-Max, and add the difference in weight to the Prius, the Prius will still far surpass the C-Max MPGs. Would any of you Prius owners like to try this experiment? Here is a high revving engine analogy...try pedaling a 5 speed bike on the flats with no wind at 10 MPH in 1st gear for a few miles. You might attain 10 MPH for a few blocks and at this rate of speed you will notice your legs are spinning the pedals at an extremely high rate. You will then notice that you will tire out very quickly. Most of your energy is spent as parasitic energy which is being expended in your legs trying to keep them peddling at this high rate...as a result, very little energy is making it to the wheels. Shifting to a higher gear will allow for more efficient energy transfer to the wheels and reduces these parasitic leg losses. Here is a quick test you can perform to demonstrate the relationship between MPGs and engine RPM. While driving your C-Max with a stabilized battery at 60 MPH on the flats with no wind, take note of your instant MPG gauge then downshift to Low and you will notice your MPGs drop significantly while your engine revs up high (this is totally safe as the computer limits the RPM to a safe range). The power needed at the wheels (load) has not changed, only the engine rpm has (input power and fuel consumption has increased). This reveals the extra parasitic energy being consumed by the higher revving engine. Now imagine what would happen to the MPG meter if you could lower the engine RPM further than it's current value when in Drive? The C-Max has demonstrated (by myself and others) that it can achieve 60 MPG just as the calculations predicted. These conditions are happening when the motor, generator, and engine are all in their safe, efficient, and designed operating parameters. The motor and generator speeds are all firmware controlled. Now we need Ford to alter the C-Max firmware to maintain this high efficiency operation at all times. Also, I am hoping that we can prevent other discussions that appear to be derailing us from trying to find a solution as to why the C-Max MPG's are so low. I hope we can exchange factual information that can help resolve this issue and help drive us to root cause. What pertinent data do you offer in helping to resolve this issue? Thank you in advance for your help in submitting this data and helping find a solution.

My math substantiates my test condition findings. Should I have made a mathematical error, please let me know. If I hear nothing then I can assume it must be correct. Also, you are right...I will keep this strictly factual and leave out any conspiracy theories. I reiterate, the C Max should be getting around 61 mpg at 60 mph...the math proves it. Ford...if your reading this...please lower my RPMs in the next firmware release! I will also volunteer to test your beta version for free. Thanks in advance :victory:

Experimenting with my 2003 Jetta Diesel revealed different MPGs going up a mile long 10% grade hill while using different gears at a constant speed of 30 MPH in each of these gears. The car attained 9 MPG @ 30 MPH in 2nd gear (very high reving engine), 15 MPG @ 30 MPH in 3rd gear, and 22 MPG @ 30 MPH in 4th gear (which had to have the accelerator pedal almost pushed to the floor and had a very low RPM). The take away is that you have to lower the Engine RPM and make it work harder to increase your MPGs. Fuel use was the main determining factor with transmission efficiency between the gears following a distant second. Here is some math to substantiate why the C-Max should achieve around 58 to 61 MPGs at 60 MPH. C-Max Curb Weight - 3,600 lbs My weight 170 lbs Total weight - 3,770 lbs C-Max average coast down time from 65 MPH to 55 MPH - 17.7 seconds Grams of Gasoline per Gallon - 2,721 g. Horse Power required to maintain 60 MPH on the flats with no wind - 15.52 HP Horse Power required to maintain 60 MPH on the flats with no wind and factoring 91% transmission efficiency - 17.06 HP 15.52 HP converted to kW - 11.6 kW 17.06 HP converted to kW - 12.7 kW RPM needed to attain 11.6 kW - 1,250 RPM (see attached. The Ford 2 Liter Atkinson engine should have slightly lower RPM values) RPM needed to attain 12.7 kW - 1,400 RPM (see attached. The Ford 2 Liter Atkinson engine should have slightly lower RPM values) To drive for 1 Hr at 60 MPH will consume 11.6 kWh To drive for 1 Hr at 60 MPH will consume 12.7 kWh (this has 91% transmission efficiency factored in) BSFC fuel consumption at 1250 RPM to attain 11.6 kWh - 230 g/kWh (see attached. The Ford 2 Liter Atkinson engine should have slightly lower values) BSFC fuel consumption at 1400 RPM to attain 12.7 kWh - 220 g/kWh (see attached. The Ford 2 Liter Atkinson engine should have slightly lower values) Total grams of fuel per hour consumed while traveling at 60 MPH at 11.6 kWh - 2,663.4 gr./hr Total grams of fuel per hour consumed while traveling at 60 MPH at 12.7 kWh (this has 91% transmission efficiency factored in ) - 2,799.5 gr./hr Calculated MPG for 11.6 kWh - 61.3 MPG @ 60 MPH Calculated MPG for 12.7 kWh (this has 91% transmission efficiency factored in) - 58.3 MPG @ 60 MPH Conclusion - Actual MPGs for the C-Max should be around the calculated values of 58.3 MPG to 61.3 MPG with the engine RPM of 1,400 @ 60 MPH. Note - due to the nature of a CVT, I doubt that there will be much if any added transmission losses when shifting into neutral at 60 MPH thus I believe the higher MPG figure of 61.3 MPG is the more accurate of the two.

Anyone have luck connecting an Engine Tuner/Flasher to download, alter, then upload a new C-Max engine/transmission map with the newly altered lower CVT RPM parameters? Opening up the CVT ratio to allow the engine to spin at lower RPMs for better MPGs under light throttle conditions will not alter the total engine HP or motor HP output thus the performance would not be altered as the engine and motor RPM and torque are allowed to operate as they do now under hard acceleration. I've seen 55 to 60 MPGs under brief but ideal conditions. I believe that by lowering the RPM we would all experience 55 to 60 MPGs at 65 MPH under the ideal conditions I described prior. I have also experienced the chevron showing charging and discharging while the instant MPGs were close to 60. I included these two pictures. All I ask is...Ford, please change my RPMs as I indicated earlier, and I'll report my findings for free...also, you can then keep the $550 check that you will be sending me due to the low MPGs...I am that confident regarding this MPG increase. Also, it would put the C-Max back in the news with a huge positive spin. Besides the current lower MPG's, I love this car!

The transmission is continuously variable and already has the ability to vary its ratio by altering the firmware settings that operate the motor and generator RPMs. If you set the electric motor RPM to 2650, set the engine RPM to 1100, set the generator RPM to -2820, the car should then go 45 MPH on the flats and obtain phenomenal MPGs. The maximum engine output power at 1100 RPM is around 12 kW (16 HP). This is sufficient to propel the car 60 MPH on the flats with no wind. The CVT can be programmed to operate the engine at 1100 RPM by setting the electric motor RPM to 3500 and by setting the generator to -5070 RPM...this will give you 60 MPH. To operate in this mode would require close to full wide open throttle (most efficient engine thermal operation), again you would receive phenomenal fuel mileage. Should you not want to operate the engine close to its maximum torque at these low RPMs then raise the RPMs roughly 10%. I would like to see a 2.0 Liter C-Max reprogrammed to allow the engine RPMs to be 1200 at 45MPH, 1400 at 55 MPH and 1600 at 65 MPH. Maybe have an Eco button that would remap the RPMs lower to the following for even better MPG's - engine RPM 1000 at 45MPH, 1200 at 55 MPH and 1300 at 65 MPH. All these RPMs would be on the flats with no wind, no accessories, windows rolled up, 70 degrees F, and while the battery was neither charging nor discharging (purely engine driven). The lower you force the engine RPM, the higher the MPGs will be.

Why C-Max Hybrids are getting low MPGs Tim Gulden 7/23/2013 Introduction - It appears that the majority of C-Max owners are experiencing 20 to 25% lower MPGs than the rated 47/47. While 90 miles into a 110 mile trip, a 2013 C-Max experienced a MPG/RPM anomaly while traveling on a sunny 65 degree day. The C-Max entered the bottom of a long level straight stretch after descending a minor slope along the Mississippi river. The RPM remained low at 1589 on the flats while traveling 65 MPH with a slight tail wind. The instant MPG meter went a little over 60 MPG and stayed there (while slightly fluctuating up and down) for about 15 seconds while the RPM remained just under 1600. During this time the battery was neither charging nor discharging and the Engage Graphical Display did not indicate any blue. Normally at 65 MPH on the flats this 2013 C-Max experiences an instant MPG meter reading hovering slightly below or spot on 40 MPG. After the above 15 second time period elapsed, the RPM went back to around 2000 RPM and the instant MPG meter went back to around 40 MPG. This above anomaly prompted the following investigation. History - Ford Motor Company independently developed a system with key technologies similar to Toyota's HSD (Hybrid Synergy Drive) technology in 2004. As a result, Ford licensed 21 patents from Toyota in exchange for patents relating to emissions technology. Theory - Ford obtained CVT transmission firmware from Toyota that was mapped to the higher revving 1.5 liter engine and used it in the new 2.0 liter Ford Hybrids without remapping the transmission to operate at the much lower and more efficient RPM range of the 2.0 liter displacement engine. Data - The following data points are based on a level stretch of road with negligible wind at 70 to 73 degrees, samples taken in both road directions, with no accessories operating, windows rolled up, and/or industry known test data was used and is noted at the end of that bullet item. The driving duration prior to the test run was of a sufficient length as to stabilize the battery pack charge so the computer neither tried charging the battery nor was discharging the battery during the time the measurements were captured. (If any battery current did happened to be flowing at this time it would have been negligible.) Maximum MPG is attained when Engine RPM is close to its lowest. Gen II Toyota 1.5 liter operates at 1900 to 2000 RPM at 55 to 60 MPH (taken from online source) Gen III 1.8 liter measured around 1248-1300 RPM at 55 MPH @82% engine load, and achieved 60 to 65 instant MPG. Gen III 1.8 liter measured around 1000 RPM at its lowest at 45 MPH and 1600 RPM at 65 MPH. Maximum engine efficiency is when the engine is loaded close to 100%. 2013 C-Max 2.0 liter engine measured 65% loaded at 65 MPH. 2.0 Liter C-Max engine should have its best MPG around 1100 to 1200 RPM. 2013 current C-Max engine RPM operates at 2000 RPM at 65 MPH and achieves an instant 40 MPG. 230 g/kWh Brake Specific Fuel Consumption efficiency for the 1.5 liter starts at 2,000 RPM. 230 g/kWh Brake Specific Fuel Consumption efficiency for the 1.8 liter starts at 1200 RPM. Brake Specific Fuel Consumption maximum efficiency for the 2.0 liter RPM should be at or lower than the 1.8 liter's lowest RPM. Running an engine at a higher than needed RPM results in high parasitic pumping losses. Running an engine at less than its maximum efficient load results in lower thermal efficiency. Conclusion – The 2.0 Liter Ford Hybrid engine is not currently operated in its' most efficient RPM or MPG range. The C-Max Transmission Firmware needs to be modified to allow the 2.0 liter engine to operate at its' lowest efficient RPM (somewhere between 1,000 and 1,200 @ 45 MPH and 1,500 to 1,600 @ 65 MPH) while maintaining its Brake Specific Fuel Consumption maximum efficiency, high engine loading percentage, and smooth engine operation. As a side note - Lower engine RPM might also result in slower traction battery charging which will help extend the battery's lifespan. Note - See the attached file for more details. Why C-Max and Fusion Hybrids are getting low MPGs 2 Printed.pdf

I experienced the exact same spark plug issue. I have worked with engines for more than 35 years and with a correct fuel/air ratio the engine should never foul a plug. Carbon fouling indicates the lack of oxygen (or too much fuel) to fully combust all the fuel. The fuel/air ratio in our cars are too rich resulting in fouled plugs, lower than rated MPGs, higher than normal fuel consumption, and accelorated engine wear. I have a second issue...upon decending a 10% grade mile long hill in hill decent mode and with a full battery, my C-Max is randomly/intermittently surging and missing as it warms up till it hits about 135F and the RPM drops to 1150 ish, then the surging and missing dissapear. At first the surging made me think I was experiencing a mini Prius stuck gas pedal issue as the surge made me almost tap a car in front of me...this happed twice, now I apply the brakes harder when stopped. I'm hoping Ford and my dealer can resolve these issues as I love the rest of the car and I would prefer not going through the lemon law/arbitration/what-ever-it-takes hassle.

I purchased my C-Max on 10-17-12...about 4,204 miles later, using the cruise whenever possible for acceleration (as I'm sure the computer is programmed for best mpg accelerating), and averaging 37.36 mpg (chart attached) while accelerating slower than everyone else and never going over the speed limit...I'm very disappointed. I see the Prius's achieve much higher MPGs (50 to 53). I would like to have a C-Max follow a Prius on a 500 mile minimum trip and have the two cars then compare their MPGs. This way you remove the human variability element and have the cars driven under identical conditions. My bet is that the Prius will be 22.6% better in MPGs. The C-Max MPG rating looks to be 10 mpg too high. I do know how to squeeze MPG's out of gallons as my 2003 Jetta Diesel is averaging 48.8 mpg here in Minnesota (chart attached). Where do I join a class action lawsuit for being deceived on my C-Max with the claimed 47 MPGs? Or is there a better way to resolve this by having Ford buy it back so I can buy a Prius. I bought this car strictly to buy American, the 47 mpg claim, and to help our country but I should not have to be misled by false MPG claims. I would more than welcome any trained Ford Rep to come by right now and drive my car on a 200+ mile trip with a balance of city and highway driving and show me that my car will get 47 mpg...better yet I will borrow a Prius and follow them so we can then compare MPGs to each other and to their respective EPA published MPGs. My guess is the Prius will be very close to its published MPG and the C-Max will fall far short of its'. As you can see, I am upset over the false MPG ratings...besides this, I do love everything else about the C-Max and have been WOWed by it many times.