New 2014 Honda Accord Hybrid

[hybridbear]

From Green Car Reports:

How the new HAH powertrain works

 

And their first drive report

Spoiler alert: they got 47 MPG combined while not driving gently. If that's legit then I think this car might be a game-changer!

[lolder]

This is another system to avoid the Toyota/Ford eCVT patents. If it works, fine. It's got a clutch, FFH's do not. It's going through a needless electric loss cycle on acceleration when the ICE is not connected with the clutch. That they achieve the economy they do in light of the inefficiencies is commendable. It's really closer to a Volt. The outcomes of either system rely heavily on execution and manufacturing but it is not an elegant design like our eCVTs. Competition is good.

Edited October 9, 2013 by lolder

[corncobs]

I still like my FFH exterior and interior styling much much better not even 5 or even 10 MPG more would turn me over.

 

If they found a way to get the MPG # save for real world driving hopefully more people will join the hybrid driver family.

[Eddie Sessum]

If it was a solid number way up there once it came out. If I wouldnt have already bought my mkz I would have considered it. But it would have to be atleast 10mpg more to deal with the looks lol.

 

We can just hope that ford follows honda on the idea for the next gen.

[gadgetguy]

I still like my FFH exterior and interior styling much much better not even 5 or even 10 MPG more would turn me over.

 

If they found a way to get the MPG # save for real world driving hopefully more people will join the hybrid driver family.

Totally agree!

[Toz]

just remember a quote from the article "From that (provided our trip computer was accurate), we're quite convinced" they were using the on board trip computer, not actual mileage. So I am guessing that they did not have the car long enough to do a real, from the pump, gas mileage.

[Aquineas]

Here's one from thetruthaboutcars.com. Very impressive numbers. I don't have buyer's envy because my wife absolutely loves the Fusion. But it does give one pause.. Edit: In the video review, he states that they're averaging about 10mpg more than the FFH.

Edited October 10, 2013 by Aquineas

[hybridbear]

This is another system to avoid the Toyota/Ford eCVT patents. If it works, fine. It's got a clutch, FFH's do not. It's going through a needless electric loss cycle on acceleration when the ICE is not connected with the clutch. That they achieve the economy they do in light of the inefficiencies is commendable. It's really closer to a Volt. The outcomes of either system rely heavily on execution and manufacturing but it is not an elegant design like our eCVTs. Competition is good.

So I want to understand this better...

Here is a link to the topic about the Toyota Prius eCVT:http://fordfusionhybridforum.com/topic/6775-what-is-an-ecvt-how-does-it-work-here-is-the-answer/

The Prius can operate in four distinct modes:

1. The HVB is disconnected (not charging or discharging) thus using the ICE only to power the car, MG1 & MG2 are neither generating nor using electricity
2. The ICE spins a generator to make electricity to power the car, the ICE is not actually spinning the wheels
3. The ICE powers the wheels and spins a generator to make electricity to power the car and/or charge the HVB
4. The ICE is off and the car drives electrically

It appears that the new HAH does Prius1 on the highway and Prius2 & Prius4 around town as needed.

 

The FFH operates in these modes it appears:

1. The ICE powers the wheels and spins a generator to make electricity to charge the battery
2. The ICE powers the wheels and the HVB sends electricity to an electric motor to power the wheels
3. The ICE is off and the car drives electrically

Does the FFH ever use the ICE as a generator to send electricity to an electric motor to power the wheels while being disconnected from the wheels?

 

I'm trying to understand all of this.

 

For more details see the article above from GCR and this article:

http://www.technologyreview.com/view/520106/ditching-the-transmission-allowed-hondas-accord-hybrid-to-hit-50-mpg/

[lolder]

The Prius and FFH operate alike. The cars can be stationary and the ICE running to charge the HVB or some other check like evaporative emissions. When the ICE runs, it is always connected to the planetary gear system that is connected to the wheels and MG1 determines how much power the ICE transmits through the CVT to the wheels. When the car is stopped, it's zero and when the car is in motion varying amounts of the ICE output may go to MG1 (in the generator mode) and the wheels. If you floor it, a large amount is delivered through the CVT to the wheels and the rest goes to MG1 which goes to MG2 along with energy from the HVB. Specifying modes is too complicated AND too simple. It's a series/parallel eCVT full hybrid. The eCVT makes it easy to juggle the power split by electronically varying the torgue of MG1 many times a second, both positive and negative in either direction of rotation. The Volt has clutches also like the HAH. The mode in the HAH where the ICE is disconnected from the gears and only runs the generator which powers the traction motor is an inefficient one but since the gears are fixed at one speed, they can't connect the ICE at low speed for significant power. It's a ( well done ) kluge designed to avoid the patents, in my opinion. Boo-Hiss to electronic clutches that have to be perfectly synchronized during engagement to avoid lurches. That was the problem with the first HSH's that were jerky. They've got that smoothed out but I worry about the long term reliability. I worry about the long term durability of electro-mechanical devices like that. There is nothing to wear or synchronize in the Toyota/Ford eCVT system. Everything is done by software and solid-state device. The only wear is in gears and bearings which usually is very low. The only other wear is long term ICE wear and HVB deterioration. The government tests showed the !st gen FFH HVB had a 8% degradation after 160,000 miles. By comparison the 1st gem ( US ) Prius had a 60% degradation. Even that amount of battery loss did not affect the Prius normal operation or mpg. It's only necessary that a non-plug-in eCVT HVB not fail. The HVB is never disconnected in these cars while in operation. In "N", most of the time the HVB will not apply power to either MG1 or MG2. It will power MG1 to motorize the ICE when the vehicle is above the max EV speed even in "N". The HVB will operate the AC in "N".

[lolder]

Understanding how a planetary gear set works is the key to understanding eCVTs. There are many places to read about them on the web and many Prius demonstations. The Fords are the same. There is a center "Sun" gear connected only to MG1; there is the "Planetary" carriage gear connected only to the ICE and the "Ring" outside gear connected to the wheels. Power can go into or out of any of the three parts or between the parts by controlling the torque on the "Sun" gear. When you do this with a computer, you have the modern eCVT hybrid.

[lolder]

Read all three pages of this thread about transmissions and clutches in the HSH forum: http://www.hyundai-forums.com/229-sonata-yf-hybrid/191282-transmission-issues.html

[hybridbear]

Ford's HF35 explained:

 

 

 

Toyota's eCVT:

 

 

These diagrams were posted on PriusChat. They show the difference between the Toyota system where the ICE, MG1 & MG2 are all in line. Whereas the FFH has the traction motor on a different axle... perhaps lolder can help explain the pros/cons of each design as far as why we see the FFH pretty much always charge the battery when the ICE is on and then run in EV for a long time compared to how the Prius rarely uses the ICE to charge the HVB and doesn't run far in EV mode.

Edited October 12, 2013 by hybridbear

[lolder]

The physical archetechture is different but a block diagram is the same except there is another planetary gear to shift MG2 speed in the gen III 2010 + Prius to allow for lower MG1 speed and a higher top EV speed. The operating points are different because of the different car weights, power and design goals. I really think they operate alike except Ford is more agressive in turning off the ICE. The ICE does not always charge the HVB when it is running in either car. They keep it at about 50%. The 2013+ LiIon may be different but I doubt by much. You need the charge headroom for regen braking and discharge for acceleration assist. That means ALL the hybrids have HVBs from 1.2 to 1.5 Kwhrs. That's all you need. That will also provide 1/2 to 4 miles EV . I got 4 miles at 40 mph right after a HVB conditioning event ( HVB discharge of 100% to 30% or 70% of 1.3 KWhrs = ~950Whrs or about 240 whrs/mile. One half mile to a mile is more likely. In the gen 1 FFH, you cycle between 50% and 30% HVB charge. That's about 260 Whrs ( 20% of the Gen 1 FFH 1.3KWhr HVB ) and that's haw miuch energy it takes to move the car a mile at about 40 mph. The Prius physical size is much smaller because they are after weight loss. The Prius can get by with 200 whrs/mile. The Prius was designed from the get-go as a hybrid and weight is a mileage killer. The Fusions are an adaptation of a non hybid and ever since the first Ford Escape Hybrid in 2004 have had a considerably larger eCVT. The Prius c has a really small eCVT. When you lower the weight, everything can be smaller. The Prii eCVTs have a drive chain, the Fords do not. The planetary gear of an eCVTs can be really small, you can hold the Prius one in one hand. The MGs are bigger and built into the transmissions in both makes.

The FFH is a really nice driving, quiet, comfortable more powerful car. The Prius is the mileage champ.

Edited October 12, 2013 by lolder

[lolder]

As an example of the problems that weight causes, in 2010 a car won the X Prize for a 100+ mpg car ( http://news.cnet.com/8301-11128_3-20016632-54.html ). It weighed 800 lbs !!!! A EPA 50 mpg Prius weighs 3000 lbs. Prii have been driven by hypermilers to over 100 mpg.

[hybridbear]

I really think they operate alike except Ford is more agressive in turning off the ICE. The ICE does not always charge the HVB when it is running in either car. They keep it at about 50%. The 2013+ LiIon may be different but I doubt by much.

Thank you for your excellent reply!! I really encourage you to go and test drive a 2013/14 FFH when you have some time because I'm sure that having experienced the changes you'll have much more insight to share with us. The 2nd gen FFH seems to be quite different from the 1st gen in that with the current gen it's rare that the ICE isn't charging the batteries when running. If we go back to the Youtube video below from the spring, the Ford engineer said that they designed the 2013 to spend a lot more time in EV mode. This is evidenced by the fact that many of us see upwards of 50% of miles shown as EV miles according to the display. In city driving you can see 70+% of your miles without the ICE running. Thus, when the ICE does run it is often loaded up with about a 15 hp load by the generator. I recently found on the C-Max Forum XGauge codes for SOC which show that the car only uses a range from about 40%-65% SOC of the HVB. 40% approximately equals an empty battery on the dash and 65% about equal a full dash battery. The dash battery graph doesn't follow a linear scale either. If very quickly moves from about 2/3 full to 1/3 on the display while the HVB actually isn't changing in SOC that much. Another XGauge code allows you to see SOC as the % SOC of the useable portion of the battery. This allows you to see that the battery icon doesn't follow a linear scale.

 

I got distracted there...back to my point... unless the dash battery icon is near full, the ICE will be spinning MG1 to send electricity back to the HVB. Only on long highway trips pre-update would you see the HVB reach this level of charge. Under normal ICE/EV cycling the ICE is always loaded up to generate electricity and charge the HVB.

 

The video can be seen two posts down by Corncobs

Edited October 14, 2013 by hybridbear

[hybridbear]

For some reason my Youtube video above didn't embed but just left a link...if anyone knows how to fix that let me know please.

 

Another reason the HAH gets such high MPG figures is that Honda invested in a technologically advanced ICE. See the quote below from this review.

 

 

That 141-hp, 2.0-liter four-cylinder i-VTEC gasoline engine, by the way, is noteworthy not just for being Honda's first Atkinson-cycle engine but for being the most efficient internal combustion engine in the world.

I'm sure the FFH would have higher EPA ratings if it had a comparable ICE to the one in the new HAH. Other articles have mentioned that this ICE sets a new record for thermal efficiency IIRC.

[corncobs]

http://youtu.be/nUwnEdPQt0g

 

Not sure what's different but posting the sharing link works. Maybe there is some additional parameter that doesn't allow the recognition for the video.

Edited October 13, 2013 by corncobs

[acdii]

I can say for sure that the ICE is nearly always charging the HVB, it is Extremely difficult to get the 13 FFH to a neutral battery status where it is neither charging or discharging. The battery is almost always used in some manner, unlike the first gen FFH. I have done some test drives on one 4 mile stretch of rural highway that is nearly perfectly flat(rare by me), and I can get it to stay neutral for a brief period while staying at speed, but a twitch of a toe is all it takes to break that, it is that sensitive.

 

I am finding that the ICE when used just to propel the car can be as efficient(not more efficient) than the 2.5 in the previous gen. It all depends on SOC, if you can keep SOC high with little draw(no AC), then you can get between 40-50 MPG at 55 -60 MPH. Not at all easy to do though, it was so much easier to stay over 40 at highway speeds in the previous gen even at 70.

[hybridbear]

I can say for sure that the ICE is nearly always charging the HVB, it is Extremely difficult to get the 13 FFH to a neutral battery status where it is neither charging or discharging. The battery is almost always used in some manner, unlike the first gen FFH. I have done some test drives on one 4 mile stretch of rural highway that is nearly perfectly flat(rare by me), and I can get it to stay neutral for a brief period while staying at speed, but a twitch of a toe is all it takes to break that, it is that sensitive.

 

I am finding that the ICE when used just to propel the car can be as efficient(not more efficient) than the 2.5 in the previous gen. It all depends on SOC, if you can keep SOC high with little draw(no AC), then you can get between 40-50 MPG at 55 -60 MPH. Not at all easy to do though, it was so much easier to stay over 40 at highway speeds in the previous gen even at 70.

Even when the battery icon doesn't indicate charging or discharging the ScanGauge indicates that there is still current flowing in or out of the battery. The Toyota hybrids will spend extended periods with the HVB basically disconnected while driving on the freeway under the right conditions. The FFH doesn't seem to ever do that. Toyota says its cars do that to make the battery last longer by not constantly charging or discharging the pack.

[lolder]

The first generation Prii ( 2001-2003 ) HVB had a 60% capacity decline in the government 160,000 mile accelerated tests. Even though there was no performance decline of the car, maybe Toyota reduced the HVB activity because of this. THe HVB is never "disconnected" because high voltage 3 phase AC is always present for the car to operate. Torgue on MG1 controls the planetary gear operation and ICE rpm. The 2010 FFH HVB declined only 8% in the 160,000 mile test.

Edited October 14, 2013 by lolder

[Eddie Sessum]

The first generation Prii ( 2001-2003 ) HVB had a 60% capacity decline in the government 160,000 mile accelerated tests. Even though there was no performance decline of the car, maybe Toyota reduced the HVB activity because of this. THe HVB is never "disconnected" because high voltage 3 phase AC is always present for the car to operate. Torgue on MG1 controls the planetary gear operation and ICE rpm. The 2010 FFH HVB declined only 8% in the 160,000 mile test.

 

What was the battery capacity decline on the previous gen FFH? I never saw the info on the prius battery on that sitebefore so im guessing you have another site you pulled that info from.

[acdii]

Even when the battery icon doesn't indicate charging or discharging the ScanGauge indicates that there is still current flowing in or out of the battery. The Toyota hybrids will spend extended periods with the HVB basically disconnected while driving on the freeway under the right conditions. The FFH doesn't seem to ever do that. Toyota says its cars do that to make the battery last longer by not constantly charging or discharging the pack.

Correct, but when you see no Charge/Discharge, it just means that the current draw off the pack is equal to the amount of energy the ICE is producing on the Generator.

[lolder]

 

What was the battery capacity decline on the previous gen FFH? I never saw the info on the prius battery on that sitebefore so im guessing you have another site you pulled that info from.

The 2010 FFH is the Gen 1 and it was 8%. The Prius and Honda results were removed from that site for some reason but here they are: http://avt.inel.gov/pdf/hev/end_of_life_test_1.pdf

See page 7 of the pdf.

Edited October 15, 2013 by lolder

[lolder]

NiMh HVB battery technology seems now to be very mature and reliable. I don't think Toyota has gone to Li-Ion yet. You don't need Li-Ion in a hybrid because you only need 1.1-1.5 Kwh. and the weight saving is only about 30 lbs. ( which car companies kill for today ). Reliability is more important than weight and power in an HEV. Once it's a PHEV, that's a completely different design problem. Toyota is very leary of Li-Ion after being very daring in designing the first Prius in the '90's.

Edited October 15, 2013 by lolder

[hybridbear]

This is one of the best reviews I've read so far of the HAH.

http://www.autoblog.com/2013/10/14/2014-honda-accord-hybrid-review-first-drive-video/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+weblogsinc%2Fautoblog+%28Autoblog%29

NiMh HVB battery technology seems now to be very mature and reliable. I don't think Toyota has gone to Li-Ion yet. You don't need Li-Ion in a hybrid because you only need 1.1-1.5 Kwh. and the weight saving is only about 30 lbs. ( which car companies kill for today ). Reliability is more important than weight and power in an HEV. Once it's a PHEV, that's a completely different design problem. Toyota is very leary of Li-Ion after being very daring in designing the first Prius in the '90's.

Li-Ion also saves space which is more important in a sedan than in the hatchback Prius.

Correct, but when you see no Charge/Discharge, it just means that the current draw off the pack is equal to the amount of energy the ICE is producing on the Generator.

The Fusion never is in this state. Even when you don't see any indication on the dash that the battery is charging or discharging (a lack of arrows) the ScanGauge shows that there is still a current flow. This is different from the Toyota hybrids which will frequently show 0.0 amps of current flow on the ScanGauge.