plus 3 golfer

Focusing on a precise definition of brake score is not the intent of the thread. What matters are the losses associated with capturing and reusing the captured energy from regenerative braking vs coasting either in neutral or in drive. If you have to use the brakes to slow down from moderate speeds, shoot for 100% brake score. Otherwise, shoot for "no brake score" by coasting or 100% by coasting and only applying the brakes just prior to stopping. That's the message I think recumpence is trying to make. Here's a few ways Ford has described regenerative braking and such seems to be consistent every time I find something on Ford and regenerative braking. So, I assume as one begins braking and as long as the friction brakes are not applied but for the last part of slowdown before completely stopping, one gets 100% brake score - that's easy. But what algorithm does Ford use when the friction brakes are applied during the slow down process. The applicable data could be captured continuously and thus a very reliable estimate of the amount of energy captured each time one applies the brakes could be computed once the car comes to a stop OR Ford could take short cuts and do a "ballpark" estimate. :) So how close is a score of 75% to capturing 75% of the available energy that would be lost to friction braking but for regen braking. I'm interested in knowing what the word "captured" means and where is the captured energy "measured". IMO, to use the word "captured", the measurement has to be at the output of the traction motor. Otherwise, no energy is "captured". If the field winding are open, no energy is captured. This makes sense as Ford states they capture over 90% of the energy normally lost in heat and recycle it to the HV battery. This would indicate a traction motor efficiency of about 90+%.

If I understand you question correctly, the answer is YES because conserving the kinetic energy in the car is better than regeneration. Coasting can be done "in gear" or in "neutral" (freewheeling). It's always better to coast if one has to slow down than to apply the brakes to slow down. This is because more of the stored energy in your car (kinetic energy) will be used to overcome the drag forces on the car than converted to electrical energy which involves a considerable efficiency loss during the conversion process. If one has to come to a complete stop, one has to apply the brake (more regen braking and eventually friction braking). Otherwise, the car will continue to move forward. In Ford's videos on hybrids, they say the car captures 90% of the available braking energy AND then sends it back to the battery to be stored. So, 0.90 is likely the efficiency of the traction motor, the inverter is likely around 95% efficient (large PV solar inverters are around 96 / 97%). Li-on battery efficiency is around 98%. I would assume the I2R losses in the cabling to be less than 1%. Since during regenerative braking the traction motor (usually referred to as MG2) is used and speed is generally slower than cruising, drivetrain losses vs freewheeling for the e-cvt transmission is likely very small so let's use 5% (this could be included in the 90% Ford states in the video). So, a better guess at the overall regen braking efficiency vs coasting (freewheeling) might be between (0.9x0.95x0.95x0.99x0.98x0.99x0.95x0.95x0.9) = 57% and 63 % removing the drivetrain losses. Again, this is very close to my estimate based from recording SOC and using speed to calculate KE while braking and getting 100% brake score. The exact number is not material. The point is that there are considerable losses in regenerative braking. On battery temperature affecting these losses, the presumption is that the total conversion process (from charging to discharging) takes place over minutes and thus battery temperature remains very stable. So, if one coasts in gear but does not apply the brakes, the regeneration efficiency would still be around 60% (maybe less if there are more drivetrain losses). But, if one applies the brakes, one slows down quicker because a larger % of the kinetic energy (KE) is being converted to electrical energy over time. In essence, the additional kinetic energy that was converted to electrical energy by applying the brakes could have been used for overcoming drag with "no regen efficiency" losses when continuing to slow down or accelerating again. So, by starting ones coasting in gear earlier, one maximizes the KE and improves FE. This is why it makes sense to try to time traffic lights by coasting and not have to stop or virtually coasting to a stop. Yes, friction brakes will eventually grab below a certain speed which to me seems to be in the 5-7 mph range but there's not much KE left in the vehicle below 10 mph. KE is a functional of the square of the speed (KE = !/2x(Mass)x(velocity)2. So at 20 mph, there's 4 times as much KE than at 10 mph. Coast, coast and coast more for better FE (time and driver following permitting). :)

Interesting because it appears that I am seeing better FE after the update on May 29 than I expected. In essence, my FE seems to be the same at 110+F ambient temps after the update as it was at about 95F before the update yet my climate usage has nearly doubled (from under 0.5 kW at 95F to nearly 1.0 kW at 110+F on average). It's difficult to tell given all the variables but it may be between 1 - 2 mpg difference on 40 mpg average. I need temps to drop back into the 70s / 80s to get better comparative data. We need someone to run a few "controlled" tests before and after the update.

In neutral, the output shaft is disengaged from the wheels and no power flows through the transmission..The electric motor does not provide power to or hold the final drive and the final drive can spin freely. Coasting to a stop in neutral or drive is better than braking to a stop. My 50-60% efficiency assumes coasting in neutral vs braking and allows drag to slow the car down. But coasting in neutral is against the law in many (probably most if not all) states as one loses an important element of control - throttle. The regen load when coasting in gear is suppose to simulate engine braking. The issue I have with coasting in neutral in "normal" driving is that it is not practical as it takes way too long to slow down and pi$$es off the drivers behind and adds a significant amount of time to ones trip. Coasting in drive while not as efficient as neutral does add some time to the trip but usually doesn't pi$$ drivers off as frequently. But coasting in drive allows more of the drag load to slow down the car than by applying the brakes (where one introduces more drivetrain and conversion losses into the mix). If I had the time and desire, I could easily run tests to record data and estimate the difference in energy of coasting in neutral vs drive. :) But since I don't coast in neutral (and am not about to start), I have no use for the results. ;) One point I forgot is that when in neutral one has no regenerative braking. So, if you have to brake one will want to shift back to drive to capture some of the energy instead of using the friction brakes.

Yes, I've said this before. Coast, coast, and coast more. From a previous post of mine: I recorded speed, time, SOC (for numerous stops from about 60 mph to 35 mph) at a frequency of about 2/3 second intervals and used topo maps, gps to adjust for elevation change (even a small change in elevation has a good bit of potential energy to be captured). Of course, we don't know the exact conversion efficiencies of every component but my rough estimate was that only about 50-60% of the total energy of the car was recovered and usable to propel the car when getting 100% brake score vs coasting. This was based on actual measured change of SOC when storing the energy through braking and then assuming that the losses associated with use of the stored energy would be about the same as when storing the energy. Even if one used conservative estimates of the efficiency of 0.95 for the major components like motor / generator, the inverter and the drivetrain, one would get an overall effective efficiency of about 73% = (0.95)^6 Drop the efficiencies down to 92.5% and the overall efficiency drops to 61%. If each major component were 90% efficient, the overall efficiency would be 53%. Here's one of the recordings I used and posted previously when testing grill covers.

The more I read, test, and analyze Hybrids. I see speed (related to aerodynamic drag) as the biggest driving factor to improving FE all else being equal. I believe the next most significant factor is allowing the kinetic energy of the car be used in slowing down the car. Even though one achieves a 100% brake score, there are still losses associated with the storage and use of the energy that likely is at least 20%. This means coast, coast, and coast more. The goal would be to drive without using the brakes. Lastly, I believe accelerating evenly and slow / moderate will enable the PCM to keep ICE in the most efficient part of the BSFC curve. Is it coincidental that the 3 coaches are: cruising, acceleration, and braking??? ;) :)

Yes, agree the computer should be adjusting load (charging) so ICE is in an efficient BSFC range. In fact, the referenced study above for the 2004 Prius concluded that the HV battery was an effective "kinetic energy" storage device compared to pulse and glide.

In a non-hybrid, it has been shown many times that one wants to get ICE into the most efficient area of the Brake Specific Fuel Consumption area as quickly as possible. Long slow acceleration up to speed uses more fuel than getting to a more efficient part of the BSFC sooner for the same given distance. Also, this is the fundamental principle as to why P&G works (hybrid or non-hybrid cars). Accelerate above the desired speed to a more efficient point of the BSFC, coast down to a lower speed than desired and then briskly accelerate back up to the more efficient point. The overall efficiency of ICE is higher than running at the constant desired speed. Wish we had the BSFC curve for the C-Max. Read Chapter 3 here. Jus, maybe you should spring for a Scanguage. :) You could then see the difference in SOC of the HV battery when running the tests. Also, you should run the tests for the same distance and your final speed should be the same under 1 and 2 bar acceleration. This is because you have traveled 0.25 miles further on the 2 bar vs 1 bar tests. So, there is fuel that would be burned to travel the extra 0.25 miles in the 1 bar test to be equivalent. Having said the above, we have to remember that the PCM controls where ICE runs in the hybrid. So, I would assume that the PCM always tries to run ICE in the most efficient areas of the BSFC. I also saw this on TDIClub recently as it also demonstrates the point. There's really no reason why Ford couldn't put this screen on the MFT (instead of that "worthless" :) energy flow diagram. We would know exactly where ICE was operating.

salsaguy, again, average is fine for fuelly and is not "worthless" - your word. Median adds little. At least the average takes into account miles driven, median does not. It's easy to see where the median falls as all cars are listed and graphed in buckets. But, why add more confusion by adding statistics (like median, mode, skewness, kurtosis, standard deviation) to fuelly or any FE site like fueleconomy.gov or truedelta.com. What fuelly needs is a big disclaimer like fueleconomy.gov on the FE pages: I have no clue what you are trying to do with your dissertation but it sounds like you want to isolate causal variables. You need regression for that not median. Fuelly doesn't contain enough nor verifiable data (like the housing market) to begin to do any serious analysis. Until such time as we know the driving conditions for each tank entered into fuelly it's pointless to argue that certain data should be excluded and that median will do such appropriately. I would expect that both the average and median FE of the 2013 fleet will continue to increase for another 4-6 months. After that I would expect the 2013 fleet FE to stabilize. The break-in and learning how to drive a hybrid are then moot. You do know that as tires wear out, FE increases by about 1.5 - 2% over the life of the tires. ;) Could this be one of the reasons fuelly is going up. :)

One can monitor your climate use on the LH display. You'll note that the use starts high to initially cool the car then settles on a fairly stable value. You can convert that average kW usage to kWh by the approximate time taken for the initial cool down and the time running after cooldown. Convert the kWh to BTUs and then BTUs to the equivalent fuel needed to run the engine (assuming an engine efficiency of maybe 35%. Compare that number to your fuel used for the trip. Everyones operating conditions will be different -- time, ambient temperature, humidity, set point temperature, number of stops where the interior heats up and so forth. Also, remember that the AC runs whether the car is stopped, going 35 mph, or 80 mph. So, the % hit for running the AC will increase as ones overall FE increases (a greater portion of total fuel consumed will be used for AC as total fuel consumed decreases with increasing FE).

So, you did not find any outstanding service items. Then based on your build date, you should have the latest MFT update 3.5.1. Is the date currently displayed on your MFT? On the clock screen you have the choice of selecting either the date or the time to be displayed at the top of the MFT screen.

Go here and click vehicle and enter your VIN: http://www.etis.ford.com/ You can check your build date and if there are any outstanding field service items.

The presumption is one is going to buy a C-Max and is indifferent to a PHEV or hybrid (not whether another model makes more sense) as I was. I may have said this before but my first solar system was with APS which offered very favorable net metering with true up in Dec each year at a payment for excess at over 6+ cents/kWh. My payback was about 3 years. Now with SRP the true up is May 1 each year with payment tied to the Palo Verde trading hub on-peak average annual price less SRP expenses. The payment for excess generation has been around 4 cents/kWh. APS will likely file soon to amend their tariff to reduce / eliminate the subsidy solar customers are receiving from non-solar customers. The AZ Commision directed them to hold a series of workshops to hear from stakeholders which I believe are over. I had cautioned my previous neighbors and friends several years ago not io install too large a system as APS could file to change their net metering tariff anytime despite what the installers might be saying. Several installed 12kW+ systems generating around 24k annual kWh with annual usage of less than 16 kWh per year. I really look for APS to propose eliminating net metering (like TX) but continue to pay the 6+ cent/kWh and ultimately tie it to wholesale trading hub prices adjusted for any T&D benefits from ones PV generation. The guys that put the oversized solar in could lose a bundle and virtually never recover the incremental cost of their excess Solar capacity on a discounted cash flow basis.

I'd suggest first discussing with dealer and then if not satisfied open a complaint with Ford. Points I'd make are: 1) you understand that the dealer / Ford is not "required" to give a loaner / rental for warranty work (but most do if the service requires more than one day as I assume Ford picks up the tab); 2) you expect that when you leave your car with the dealer, the work will be done correctly; 3) you should not have to be inconvenienced a second time by being without a car a full day because of their errors / mistakes (and perhaps even more times since you have no confidence they will do it correctly the second time); 4) A dealer employee can certainly drive a loaner (or SM's personal car) / "rental" to you and pick up your car; 4) you will open a complaint with Ford if not in agreement on how to resolve.

I guess the OP is gone. If you are still following this post, here's my analysis on my current system with SRP. I initially sized my system to hedge electricity prices while maximizing overall and incremental returns and payback. There's an optimal system size that going beyond reduces the overall return and significantly reduces the incremental return because of the utility's buyback tariff. My 4.94 kW solar system was commissioned June 10. Based on 17 days of operation, I am generating more than I anticipated given the conditions and thus will likely hedge 85 - 90% of my home usage. If I added 3 more 260W panels, I could add the load of charging an Energi and have my annual electric bill be virtually the same as it will be now. But the biggest problem is the cost to add capacity to an existing system is significantly more than the initial installation. To compound matters, since I do not have enough inverter capacity, I would need to replace the inverter at maybe $3k. Also, it would be at least $3k for the other equipment and the Solar installers cost to get the system "re-approved" and commissioned (certified installer must do the work and SRP must approve). So, after tax credits and incentives adding such PV capacity to my existing system would be a huge mistake.. Even if the inverter had sufficient capacity, the best I could likely do now after credits is spend $2000 upfront to charge an Energi vs paying SRP an additional $131 using my existing system the first year - a simple payback of 15+ years. Add to this the additional gas used in the Energi over the Hybrid for the non EV miles and the payback jumps a few more years. Had I opted to install the 3 panels initially (and bought an Energi), my out of pocket cost (after credits) would have been only $1400 more for the larger inverter and 3 panels. But even so the simple payback is over 10 years. Adding the additional cost of gas for the Energi vs the Hybrid for non EV miles and the simple payback could easily be over 12 years. I look at a car as a depreciating asset and believe it makes little sense to invest capital in an asset that supports a depreciating asset without a very short payback. I doubt I will be in my house 12 years or own my C-Max for 12 years. Of course, this analysis begs the question as t whether the Energi cost premium in AZ over the Hybrid makes financial sense to begin with.

Since I moved from SW PA in 1999, I've never had an alignment done on a car I've owned, never had uneven tire wire, haven't replaced any suspension parts, and rotate tires every 10k miles. Mileage on 4 vehicles when I got rid of them were between 145k - 195k miles. IMO, road conditions (especially potholes, uneven pavement and so forth) alter alignment slightly causing uneven tire wire and eventually the need for an alignment / tire rotation more frequently than 10k miles. Otherwise, with tires that last 40k+ miles rotation every 10k miles should wear the tires fairly evenly. One other point and that is I have been running higher pressure in my tires than recommended for quite some time. My experience is that if I run the recommended pressure, the front tire edges wear faster than the middle (and I always buy Michelin :) ). ScubaDad, what uneven wear are you getting? I check my tires at least once a month for air pressure and always look for uneven wear. I would suggest that you check the tires monthly, and if you see any uneven wear, get the tires rotated. Otherwise, 10k should be fine. If it's the front tire edges, try more air pressure.

The closest World Food (although we like the store) is too far to drive for "up close" parking. :) One probably has to get local communities to pass laws on restrictive parking in order for enforcement of such signs on public property. On private property, I believe the owner of the property has the right to have vehicles towed with little, if any consequences especially if signage clearly indicates the parked vehicle is in violation. So the question is does World Food (likely in a shopping center) have the owner's permission to have unauthorized vehicles towed. I wouldn't want to pay a $150 tow / storage bill if I decided to park in a "fuel efficient" space to get my vehicle back even if I thought I was right (my Jetta TDI was more fuel efficient than my C-Max). A hundred yard walk trumps $150.

You have to pay for the data (that's how JD makes it's $) and then I believe it's only available to the specific automaker. So, unless it's "leaked", I doubt we'll ever see specifics.

But Ford in general scores poorly in the IQS surveys. It's not just 1st year models. Also, do other 1st year models score 222? This IMO, it's a "cultural" issue within Ford. Just like Ford's old "Quality is Job 1." Saying is easy, doing is hard. Ford needs to look within not "blame" the EPA tests, MIcrosoft, or the consumer for reasons. Mulally certainly turned Ford around from the Bill Ford and his recent predecessors eras. But it's time to move Ford up to the top echelon of automakers. How do other manufacturers get to the top echelon and stay there? Ford is behind GMC, Chevy, and Chrysler (IMO, not good for Ford).

Ford can defend their lack of performance on the JD surveys and on driver's not getting better FE however they choose to. But bottom line if the average customers aren't getting close to the EPA numbers in the real world and aren't "smart" enough or speak "clearly" enough to use MFT, Ford will lose the "battle". Blaming the customer for such performance is not good for marketing and generally doesn't win customers over.

That's a "feel good" screen. It makes you feel good when you show others and explain it and they go "wow how neat" but otherwise kind of useless to the driver. Good for sales people too. Probably added for marketing purposes.

The ambient air temperature sensor is in the RH mirror (passenger side). I assume it's the little nub projecting from the bottom of the mirror. The sensor is connected to the PCM. Generally, when a sensor fails, the control algorithms use backup values as a proxy for the failed sensor although this may not have a backup but likely is the backup should the engine intake air temperature sensor fail. You may want to test with some ice on the nub and see how the temperature behaves. There may even be some test screens in the MFT (note: I need to again find how to enter the screens and put in glove box so I don't forget). The fact that the temp swung to extremes suggests that the sensor resistance went from infinite (open circuit - low reading) to zero (short circuit - high reading). It looks like P0072 and P0073 are DTC for Low / High ambient air temps which may be in the MFT test screens or perhaps in the Engineering Test Mode (IIRC do show DTC) since these are Powertrain Codes.

Compression ratios have been increasing in modern engines while still using regular fuel. There's been significant engineering into the combustion process including piston and cylinder design, multiple injections per cycle, higher injection pressures and so forth such that gas engines can now run at higher compression ratios on regular gas. Bottom line: CR alone does not dictate the use of premium fuel. I also serious doubt that if premium fuel would yield 6% better FE (% price spread between 91 and 87 octane fuel), Ford would recommend regular. Ford would be talking EPA of 50/50/50 on premium. ;).

I bought my car on Dec. 23. Sirius is still working this morning. We'll see how long it works before it's turned off. I got an offer in the mail about a week or so ago to renew my expiring subscription. It was 6 months for $30. On previous cars over the past 5 years, I've always been able to get 6 months for between about $20 - $27.

Many confuse preignition with detonation and talk about both as one but the two are quite different but they can be related. Higher octane reduces detonation not preignition. Preignition is the igniting of fuel prior to the spark by an ignition source. Regular or premium fuel can ignite before the spark and is usually caused by a hot spot in the cylinder for example deposits. This does not necessarily cause detonation or knocking. Detonation is the explosion of the last portion of fuel in the cylinder after spark or preignition instead of burning normally. Higher octane fuel reduces the liklihood of detonation because in essence the fuel flame spreads more slowly as it burns the fuel in the cylinder. If the fuel burns too fast based on when the fuel is ignited from the spark plug firing or preignition source, the last portion of the fuel can explode or detonate. This explosion is the knocking, pinging that one can sometimes hear. Also, engine run on hasn't been an issue for quite a while as modern cars stop injecting fuel when the ignition is turned off.