Consumer Reports MPG Result For 2013 Fusion & C-Max Hybrids!

What were the weather conditions for each test?

 

That's only part of their test. Do you have just the 65mph cruise control broken out? That still would no be real world indicative mpg.

 

Denial is not just a river in Egypt

 

Prius V had tailwind both directions. Is it what you want to hear?

 

It was meant to be comparative. If you drive most of the miles at 65 mph, those are what you will likely get.

 

Let's ask that question then. Bob Wilson got 52 mpg on a flat stretch of road, warmed up engine, no ac or heat. CR got 55 mpg both with the gen III prius. I don't know the temperature, adjustments, and how much was done at lower speeds to get the CR results, but I doubt I would ever get it.

Now when will I get Bob's number - If I drive on a long distance on the OEM tires, without heat or air conditioning

What can I expect? I got lower numbers, because I still have the start up penalty on most trips as they are less than 15 miles. I also get penalties for air conditioning and heat. The longer the trip the less of a hit I get from air conditioning.

That is why I didn't think the CR number is a good real number. I can't figure out why its higher than bob's And it doesn't take any account of HVAC or cold start penalty. YMMV

IMHO it likely is instructive on the differences, but I don't really trust CR accurately accounts for changes of temperature, especially since they did hit articles against the prius c and volt.

Also if I am on a long trip, I'm going 75 mph, but again YMMV. That's the speed of the motor trend test. It definitely favors the prius liftback versus the c-max or prius c. But I don't spend a large percentage of time on long trips.

 

One of those was me. I was using cruise control and the numbers of course exclude the mileage getting up to speed. Overall my best tank has been 44 mpg but I am about 42 overall. Personally I don't think I would describe the cruise control as well tuned. I have seen mileage on the same stretch of 65 mph freeway with cc on be anywhere from just under 40 mpg to up over 50 under similar conditions(temp, SOC, wind, etc). It could be that small variations in those things make a big difference. I have seen mileage drop when I slowed down from 65-55 because at 55 it would kick in an out of EV mode(again cc was on) and when it was out of EV mode the mileage would be at 20 mpg while recharging the battery. None of this has been consistent though so I really don't know what is going on but I think better programming on when to use EV or the gas, how aggressive the regen is, etc could make a big difference. For one thing I think the regen is too aggressive making the mileage take a bigger hit than it needs to when the engine is on. Just my opinion.

 

Thanks!

I tried to join the Ford forum to request the data you'd already posted.

Comments inserted:

One of those was me. I was using cruise control and the numbers of course exclude the mileage getting up to speed.​

This is the way to do it.​

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. . . Personally I don't think I would describe the cruise control as well tuned. I have seen mileage on the same stretch of 65 mph freeway with cc on be anywhere from just under 40 mpg to up over 50 under similar conditions(temp, SOC, wind, etc). It could be that small variations in those things make a big difference. I have seen mileage drop when I slowed down from 65-55 because at 55 it would kick in an out of EV mode(again cc was on) and when it was out of EV mode the mileage would be at 20 mpg while recharging the battery.​

I felt the accelerator was sensitive to the point of twitchy. The Prius come with three accelerator modes: ECO, NORMAL, PWR. I felt like the CMAX was in PWR mode during my drive . . . especially when accelerating from a stop. We know 'frittering' the accelerator hits Prius mileage and I think a reasonable place to look would be in throttle and air-flow being 'noisy' instead of seeing a steadied or desensitized mode.​

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None of this has been consistent though so I really don't know what is going on but I think better programming on when to use EV or the gas, how aggressive the regen is, etc could make a big difference. For one thing I think the regen is too aggressive making the mileage take a bigger hit than it needs to when the engine is on.​

This makes sense but the CMAX community need metrics for analysis. Your community might look at AutoEnginuity, a Windows based, OBD scanner with the ability to record data. They make model-specific versions and I suspect their Ford variant might have the type of metrics needed. It is certainly worth a phone call.​

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I want to thank you for coming over for a visit. I admire your fact-based approach to analysis. Do share with the community my attitude that if a 'Govnmnt bureaucrat' got the high mileage, don't give up. <grins>

Bob Wilson

 

Hypothesis:

The Ford accelerator and cruise control laws may be too aggressive in trying to follow the input leading to 'control loop' noise. Trying to follow the 'inputs', the Ford may be over controlling the drive train, a type of noise that leads to a lot of unnecessary, POWER-REGEN-POWER-REGIN ... mini-cycles.

They are called 'proportional-integral-derivative' PID controllers and it is the fine art (it is one of the black arts) to get the three factors right. There is a lot of literature about how to approximate an initial set of PID controller constants but then you have to 'take it to the lab' and make them work.

We know in the Prius world that trying to 'maximize reg icons' leads to poor mileage. If the Ford system is doing this in 'small scale', it could lead to the same, poor mileage, result. One of the reasons I drive primarily using cruise control is to get my clumsey, manual, foot out of the control loop.

NOTE: a hypothesis needs testing . . . otherwise it is just idle speculation.

Bob Wilson

 

Regen ability may be another area to look into.

Toyota has said that NiMh is still better than Lithium for regen charge absorption. Has anyone measured how much power C-Max hybrid can recharge? Since it is a much heavier car, the importance of regen brake is higher.

 

I don't really trust the toyota rumor mill statements.

A lithium battery of the same size in kwh designed for hybrids with the proper bms should be able to absorb more power from regen braking.

Toyota has said their engineers prefer nimh. I can only take this as puffery. Its a grand statement where you can't measure the truth. The alpha and prius phv use lithium

When toyota says nimh are better, they have typically meant less expensive. I don't think they will continue to be less expensive. Toyota has stoked the rumor mill in the other direction. Gen IV may be built in NA. Toyota is looking for a north american lithium battery supplier, but not a Lithium battery supplier. Why? The need for nimh traction batteries is short term, in the long term toyota like everyone else will be lithium chemistries.

 

Of course, I did a self validation from observing my PiP's lithium battery performance.

It can discharge about 200 amp at about 207 volts providing about 41 kW. During regen, the highest I have seen is -132 amp or about -27 kW.

I don't know how that's compared to Gen3 NiMh can regen from 201.6 volt battery pack but as I recall my Gen2 NiMh can hit max of +/-100 amp during discharge/recharge.

C-Max Hybrid HV battery is rated 35 kW. The question is, can it regen at 35 kW?

 

I don't know? USB intimated that lithium might be part of the problem, but.... there really is not any problem with the lithium it is superior. It does require that you actually spend money to design it in though, and requires different software. For Ford the point was at this redesign. Toyota has kicked the can down the road, and I doubt they will be heaily burned by it, but this is not progress.

Gen II to Gen III prius, not much better mileage - what is the point?
Gen I to Gen II prius, not much better than the EPA - what is the point?

You can argue against progres, and many do. The gen I - gen III is a major change, including much better acceleration, handling, traction, room, and mileage. Toyota didn't get there in one step, it was many small changes

 

I doubt that it can regen 35 kw for a long period of time. There are heating issues. I suspect that it can regen better than the prius v, but.... it is a heavier vehicle so more power is available to regen. A couple of reviewers have commented negatively on both the prius and c-max brakes. There are fewer complaints on the camry hybrid brakes. The energi and prius phv have different battery chemistry than the ford hybrids. It will take someone with a scan guage to measure regen.

Regen braking and pedal feel are likely places that the ford hybrids can improve.

 

From what I am seeing, these high power lithium can't recharge as fast as it can discharge. I am not saying it is a problem but simply stating an observation.

I was asking to see if owners pull the info to explain (perhaps part of it) these lower than EPA real world MPGs.

Perhaps there was another good reason why Prius v with Lithium battery and 3rd row (heavier) wasn't offered in the US with more aggressive EPA test cycle.

 

That's much better. Do not assume I follow Toyota's statements like a bible. You have a tone that thinks I do.

 

That is likely true, but given the same energy (kwh), in a lithium built for power, it should be able to charge faster than a nimh. There are heat issues with lithium chemistries so you can not charge them too fast. Since the lithium battery will be smaller, its harder to draw away this heat, which means lithiums advantage here will be less than if the batteries were the same physical size.

The prius to c-max highway numbers can be entiresly explained by cdA - drag times frontal area. In order to get epa figures you either need to be going slower 60 mph or less or the ford system must be much more efficient than the toyota system. We don't really need to look at the battery here. That would be in the city test where at least CR got better fuel economy in a c-max than prius liftback. I don't trust the CR test though.

I assumed it was because americans are larger people. Toyota dropped the third row in the rav4 because it was not selling well. It is definitely true though that the CARB waranty requirements likely had something to do with it. Even if in the lab life is much longer, it is difficult to predict aging for 10 years. Ford may have a new test that helps in this prediction, but we won't know until 2022 if the panasonic lithium cells really last 10 years in the prius phv, alpha, ford energi and hybrid. Toyota is very conservative.

 

Which is why I asked about the weather. Changes in temperature and winds can lead to changes in the fuel economy of the same car. Unless the testing was on the same day, comparing CR's numbers for different models has to be taken with a grain of salt. That is just the limitations of testing outside, on public roads, and with different drivers.

The lower drag of the Prius likely lead to it doing better than the C-max, but we can not call how much the difference is because variables were unaccounted for.

 

Toyota is not some PR machine... they have been quite open why they like Nimh over lion currently.

And they have purchased enough stake in lithium ore mines to supply 2x needs of total Japan usage right now.

But we can talk about lithium or whatever all we want, fact is, Ford hybrids get easily 10 MPG less than advertised and no amount of our talk will change that ever. We dont have a single case of owner hitting EPA for these cars over the complete tank. Whats there to defend?

So you can want to support Ford all you want, purely from patriotic reasons obviously, but there is no need to make Ford owners feel stupid by constantly telling them how they should check tires, wait for summer, or 20,000 miles or adjust their driving cycle and whatnot.

Unless Ford does some recall to replace faulty parts that are preventing these cars to reach EPA mpg, they will never be able to reach it.

I suggest that everyone who feels comfortable in justifying this as just Ford doing business, buy Ford Hybrid and show by example their owners how to reach that magical number 47.