Ford wants a new mileage standard

I thought this would be the case when I first heard of the car's high P&G threshold, but I am doubtful of this explanation now that more data is available.

P&G at speeds greater than what e.g. a Prius vagon can operate at should let the C-max whip the vagon when driven in a P&G mode, and match the vagon otherwise. That is not the case. Since the vagon is not superior based on aero, I presume the answer lies in programming, ICE efficiency, or transmission.

 

Maybe if it were a true pulse & glide. Instead it is a cycle which involves using EV battery power then cycling back to ICE power to maintain forward motion AND recharge the EV battery. We both know how inefficient that is. So there is no true glide where you travel for a long distance using nothing but kinetic energy.

 

Perhaps I misunderstood you -- I thought you were saying that mode in EPA testing explains the 47 mpg, that is rarely duplicated by car owners.

If so, then the C-max should ~ match the vagon when driven without that mode, and beat the vagon when the mode is invoked.

I understand that the Ford programming charges the battery to allow more EV driving, and I agree this is an inefficient cycle. I'm reminded of GM's propaganda that their (never to be made) serial hybrid would beat the Prius. They were wrong for the same reason, and copied the Prius instead.

However, P&G at it's best does not drain the battery. The problem with trying to invoke P&G on the highway in the C-max is that the car slows down too quickly from drag. It is just not practical or confer an advantage on flat roads. Hilly (not mountain) driving might be different.

 

Agreed. Drag is just too great to make pulse & glide efficient on the highway AND it can't be done efficiently without allowing the vehicle to lose speed.

 

Besides, if the EPA test method only has the vehicle traveling at 60mph for 12minutes I wonder what part of the cycle they are in during that test. Is the battery full and using a lot of EV? Is the test avoiding the bulk of the recharge part of the cycle?

 

Nothing wrong with this as supplemental, but very few of us consume the majority of our fuel on the flat and level, at constant speed, at good temperatures.

That was one of the findings of the national research council when trying to determine how much speed limits would effect fuel usage. Most of us have stop lights/signs, traffic, hills, weather, and a warm up penalty. That's why there are 5 cycles on the test. Unfortunately we don't even get all the cycles reported to us.

It would be good to get 55, 65, 75 cruise control mpg. Clean mpg tried to produce this chart for prius, prius v, and c-max. Tesla has a tool on their site that includes temperature to calculate your own. These tests would likely favor diesels over hybrids. I don't think epa should require this, but perhaps the FTC should for any mileage claims. Having at least a 70 mph, or higher cruise in epa calculations would help make the stickers more accurate for the c-max/fusion. Ford was looking for suggestions of what to put on their website, and use in an ap for users to guestimate there own. You might be someone good to suggest things for such an app.

 

But it isn't a fixed mixture. It is just electricity used for the mpge numbers on the sticker.​

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Yes, there was a mpge number using a fixed gasoline:electricity ratio also on the sticker in the beginning. When it became apparent how useless it was for consumers it was dropped. IIRC, first year Volts are the only cars to have such numbers on their sticker.​

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MPGe isn't just to allow straight forward comparisons between electric and gas vehicles. It will also allow the comparison between gasoline and natural gas or hydrogen. Diesel consumption can be compared with it too.​

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It may be dumbed down(it did come out of a focus group), but the watts efficiency isn't withheld on the sticker or EPA site.​

It comes down the engine's efficiency at the load it is propelling and charging. The Hyundai hybrids does it while cruising, and the economy drops when the driver doesn't allow it to do so.

 

Aye but that is not the case it seems with the CMax. It also doesn't make sense due to energy conversions. Is that why the Hyundai hybrids don't achieve stellar fuel economy either?

Here is info on the 60mph steady state driving "tests".
C-MAX Hybrid - 60 mph steady state MPG test - Page 6 - CleanMPG Forums

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I respect all the hypermiling techniques and all the tech. cycles discussion here. I think it is more fair to structure the test in a way that results would be closer to an everyday driver. Drivers who chooses to drive their cars to the fullest mpg potential should be rewarded by well over the number from the test results. IMHO consumers should not have to try so hard and barely or still fail to get what the "optimal" results from EPA.
My worst tank with my Prius was 36.7 mpg (changed to 17"wheels) and my last one was 48 mpg (with painfully slow driving and drafting) both hand calculated. I don't see myself driving this way every tank

 

And if drivers become even more aggressive and stupid, should the EPA recalculate the sticker downward ?

Is the EPA testing the car, or the driver ?

 

I'll try to make my point a little more clear. I am not talking about drivers of both ends of the extremes. EPA results are on the Optimal side and you are talking about the "Aggressive" side. Like all things, somewhere in the middle and we should have a general consensus.

If the Hybrid comes in EV, Eco, Normal, Power mode, then maybe we need more than one number on the sticker.

 

Any mpg you get with your aftermarket tires is not subject to valid comparisons with EPA ratings. Nor should winter avg. mpg be used as a comparison unless one also compares summer mpg which is typically 3-5mpg higher.

I've said it before but I'll say it again. I can't wait to see what happens when a Cmax owner swaps out the super efficient Energy Saver A/S tires for something non-LRR. Eek!

As discussed before, the EPA tests within the guidelines of most laws. We can't expect them to test cars driven at speeds exceeding the speed limit in most of the country. If you are not achieving EPA numbers or greater and your average cruising speed on the highway is 70+mph then blame yourself not the EPA. Just rest assured that any other vehicle will also do worse at higher speeds. (Not directed at Wil)

 

actually the EPA results are not really on the optimal side. I feel, at least for the Prius, the EPA rating is middle ground. Even with aftermarket 17" wheels/tires I am able to achieve the EPA rating and higher during the summer assuming I keep my speeds near EPA test levels. If I drive fast and aggressive then mpg drops accordingly but it is still well into the 40s.

Conversely, if I hypermile I will get well above EPA.

Wil, have you driven a Prius though an entire yearly seasonal cycle or are you basing your thoughts entirely on your new 2013 with upgraded wheels?

 

F8L, I am with you 100% on that, I've read your posts on tires and wheels before I made the decision. I was just trying to point out how much effort is required to achieve optimal results. Everyday consumers should not have to try so hard. How many owners do you think actually understand the Hybrid system, and would go into detail about energy cycles?

 

You know I'm a newbie owner I have been able to get over EPA results, I am not crying about not being able to meet them. It's just the fact that so much effort is required. The amount of time I researched and practiced hybrid driving techniques is not what an "average" owner would do. I also have alot of track experience, so throttle control is second nature to me. With all that, it is still not easy for me to get good results.

 

Sure sounds good. They also need to model heat, cold, etc. Is there an app for that? I guess you could have your phone monitor your commute for a week, and given your location, deduce weather for the year, then plug into a company website to tell you what various cars would average for a year. Perhaps we can crowd source commutes, and get them together, for the epa to devise better tests. I'm not sure what information we need from various manufacturers. Cold start consumption, and hill consumption are the killers for me on my prius, the happy surprise is traffic jam performance.

I'd say that is an instrumentation thing. Manufacturers could give us many instruments, I don't see why they could not add a bsfc curve. I'd prefer colored needle zones, so that you know intuitively what acceleration is doing, too little may be worse than too much in some situations.

Yes, but most of the population does not really want to go through ground school to learn to drive there cars. I can see them using an app on their phone though. figure it out, I'll code it, ford is offering cash for the app.

 

That's the beauty of the Prius, bru. You don't need to understand anything other than the faster you drive the worse your mpg. The Prius is designed to just get in and go and still get within 5%+- of EPA. Assuming mild conditions no effort is required to achieve 50mpg with OE equipment. This is evidenced by Fuelly.com numbers which show an average of 48mpg for the GenIII 2011-2012. The 2013 doesn't count because those have not been driven through a summer cycle yet.

The CMax and other new cars are trying to game the system with these automated discharge/charge cycles.

Wait until summer hits. You'll be amazed at how much more efficient you car is even with the kickass wheels! Well, assuming you are not driving in rain the whole time. I know that is not realistic in the Seatac area but you get my drift.

 

I know, brother. But you have been exerting all this effort during a winter season when it is wet and cold. Mpg drops quite a bit in such conditions. Even us NorCal folks observe a 5mpg drop with winter temps and winter blend fuel despite not getting near as much rain as you PNW guys. Just wait until summer.

 

Yes I've noticed this occurring and it seemed odd to me as well. It seems it would be more efficient to me to disengage the generator/electric motor and let the ICE work to propel the vehicle only. When the ICE is working to both move the vehicle AND recharge the battery, the performance isn't as good as it could be.