Accord Hybrid 4000 Mile Impressions
#11
03-23-2005, 11:11 AM
Hi Lewis:
___I am working with BlueSkies for some time behind the wheel of his own AH. He just swapped out the OEM Moly load with some 0W-20 last week in fact. He won’t run 50 #’s but he will run 44 which is a good start
___Although I have never driven the AH, using Assist is not a good idea for maximizing ones FE unless it will keep you in ECO mode. The gasoline needed for recharge whether hidden or not is more then using the ICE in the first place. With that, I am almost positive that “Driving w/ Load” with the AH’s ECO mode is the fastest way to hypermiling success although you do bleed off quite a bit of speed depending on the increase in height.
___Good Luck and keep us informed as to your progress.
___Wayne R. Gerdes
___Hunt Club Farms Landscaping Ltd.
___Waynegerdes@earthlink.net
___I am working with BlueSkies for some time behind the wheel of his own AH. He just swapped out the OEM Moly load with some 0W-20 last week in fact. He won’t run 50 #’s but he will run 44 which is a good start
___Although I have never driven the AH, using Assist is not a good idea for maximizing ones FE unless it will keep you in ECO mode. The gasoline needed for recharge whether hidden or not is more then using the ICE in the first place. With that, I am almost positive that “Driving w/ Load” with the AH’s ECO mode is the fastest way to hypermiling success although you do bleed off quite a bit of speed depending on the increase in height.
___Good Luck and keep us informed as to your progress.
___Wayne R. Gerdes
___Hunt Club Farms Landscaping Ltd.
___Waynegerdes@earthlink.net
#12
03-23-2005, 04:50 PM
Thought I'd chip in w/ my own observations, based on the comments I've seen in this thread...
VCM can be achieved fairly easily in the car. The specs say that it can be engaged from 20-82mph, although I've been able to get it to kick in from a dead stop at about 18mph. It will hold this to just above 15mph, but the engine will lug noticably - thus, I try to keep about 20 or so when I'm in the office park where I work at.
There are two main ways to engage it...
The first is when you back off the accellerator ever so slightly (you're signalling that you want to cruise). The ECO light immediately goes on, and if you accellerate slowly, it will remain on. If you goof up and take it out of VCM, it'll go right back in as soon as you ease up on the go pedal.
The second is accellerating slowly from a dead stop, and you haven't backed off the accellerator, but the ECO light comes on just after 42mph (that's when either 5th gear occurs, or the torque converter locks up - I'll guess the former, based on my '01 AV6 and it's shift points, and the fact that I detect what I think is the TC lockup at about 48mph). I can still be accellerating, w/ the ECO light on.
I almost never get to call IMA for boost - usually when I see it come on is:
a. When I get to almost the crest of a hill (wish it came on a little earlier, so I wouldn't lose so much velocity going up!), I see about 1/4 boost (as opposed to 'feel') and it immediately goes off when I crest. It's generally not on for more than a second.
b. After I've started up from a stop with a lot of regen (either through engine speed or braking, and usually both). I'll see the boost come on quickly about 3/4 of the way as I get to the end of the accelleration cycle.
From what I know about the engineering of the planned SoC, I'm thinking that it's just 'bleeding off' the excess charge given to it in that state. (the system tries to maintain between 80% / 20% of max / min charge level), and I almost always have 4/6 bars in my BAT meter (I live in a suburban / rural area, and I take routes that let me continue with as few stops as possible).
If you drive in stop-n-go, you'll eventually stop seeing this bleed-off, as it's using the stored charge a lot more for auto-stop, etc.
This second scenario is what I think Lewis is experiencing in his 'volunteering' scenario that he describes in the earlier post. With my driving habits / terrain on my usual routes, I almost never get to use IMA boost with any degree of effect or regularity (save for the scenarios I describe above).
I think I've said this in an earlier post, but it's worth repeating, IMO... the greatest efficencies to this car's FE are not to be had with the IMA system, but with VCM, especially given how easily it engages, and with practice, stays engaged.
IMA is valuable, but I'd give the nod to VCM over IMA about 55/45 w/ regard to FE improvement.
My next exercise is to find out where the discrepancy lies between "ECO always means 3 cylinder operation" and "ECO means most efficient usage - but not necessarily VCM-enabled". I've seen both stated, and I'd like to know definitively. Sometimes I can feel the kickdown to VCM, other times, I can't. So I want to see some more authoritative info on this.
VCM can be achieved fairly easily in the car. The specs say that it can be engaged from 20-82mph, although I've been able to get it to kick in from a dead stop at about 18mph. It will hold this to just above 15mph, but the engine will lug noticably - thus, I try to keep about 20 or so when I'm in the office park where I work at.
There are two main ways to engage it...
The first is when you back off the accellerator ever so slightly (you're signalling that you want to cruise). The ECO light immediately goes on, and if you accellerate slowly, it will remain on. If you goof up and take it out of VCM, it'll go right back in as soon as you ease up on the go pedal.
The second is accellerating slowly from a dead stop, and you haven't backed off the accellerator, but the ECO light comes on just after 42mph (that's when either 5th gear occurs, or the torque converter locks up - I'll guess the former, based on my '01 AV6 and it's shift points, and the fact that I detect what I think is the TC lockup at about 48mph). I can still be accellerating, w/ the ECO light on.
I almost never get to call IMA for boost - usually when I see it come on is:
a. When I get to almost the crest of a hill (wish it came on a little earlier, so I wouldn't lose so much velocity going up!), I see about 1/4 boost (as opposed to 'feel') and it immediately goes off when I crest. It's generally not on for more than a second.
b. After I've started up from a stop with a lot of regen (either through engine speed or braking, and usually both). I'll see the boost come on quickly about 3/4 of the way as I get to the end of the accelleration cycle.
From what I know about the engineering of the planned SoC, I'm thinking that it's just 'bleeding off' the excess charge given to it in that state. (the system tries to maintain between 80% / 20% of max / min charge level), and I almost always have 4/6 bars in my BAT meter (I live in a suburban / rural area, and I take routes that let me continue with as few stops as possible).
If you drive in stop-n-go, you'll eventually stop seeing this bleed-off, as it's using the stored charge a lot more for auto-stop, etc.
This second scenario is what I think Lewis is experiencing in his 'volunteering' scenario that he describes in the earlier post. With my driving habits / terrain on my usual routes, I almost never get to use IMA boost with any degree of effect or regularity (save for the scenarios I describe above).
I think I've said this in an earlier post, but it's worth repeating, IMO... the greatest efficencies to this car's FE are not to be had with the IMA system, but with VCM, especially given how easily it engages, and with practice, stays engaged.
IMA is valuable, but I'd give the nod to VCM over IMA about 55/45 w/ regard to FE improvement. My next exercise is to find out where the discrepancy lies between "ECO always means 3 cylinder operation" and "ECO means most efficient usage - but not necessarily VCM-enabled". I've seen both stated, and I'd like to know definitively. Sometimes I can feel the kickdown to VCM, other times, I can't. So I want to see some more authoritative info on this.
#14
03-23-2005, 05:32 PM
Variable Cylinder Management; when the computer detects that speed can be maintained on 3 cylinders instead of 6, and shuts them down
VCM has been around for a long time (most notably in the Cadillac V8-6-4 system in the 80's, which worked badly - you'd be cruising in 4cyl mode, but it would take forever to get all 8 fired up again if you needed it).
In Honda's version, here's what happens:
- fuel cut on the rear fuel rail
- spark is maintained, which minimizes plug temperature loss and prevents fouling induced from incomplete combustion during cylinder re-activation. Sparking in air alone results in higher voltages than in a fuel-air mixture because of the higher insulation resistance. Thus, Honda used iridium-tipped spark plugs are used because of their high resistance to wear at high voltages.
- Intake / exhaust valves sealed on the out of service bank of cylinders (the rear, in this case, because the catalytic converter gets to remain at an optimal temp, and because the front bank gets the best cooling efficiency)
Sealing the valves cuts the inefficiency of pumping intake / exhaust out of idling cylinders (and improves FE in the process)
To improve the ergonomics, Honda also employs a noise-cancellation system through the audio speakers, because normally, an engine running on half it's designed capacity produces an annoying booming noise. The noise still persists, but by introducing a complementary tone at just the right frequency, the noise is 'cancelled', and you don't hear it (it still works if you have the radio off).
Honda also has this system in their upper-end trim on the Odyssey van, with the 3.5L V6. Given that the J30 and the J35 are Honda's V6 workhorses, I'd like to see this adapted to every V6 in every carline (Honda *and* Acura). Or at least make it an option in every carline. Only works well w/ V6 engines, though...Wayne reported that the Honda engineers tested it on I4s and found that it just wouldn't pass muster with consumers (not enough power on demand, fast enough).
VCM has been around for a long time (most notably in the Cadillac V8-6-4 system in the 80's, which worked badly - you'd be cruising in 4cyl mode, but it would take forever to get all 8 fired up again if you needed it).
In Honda's version, here's what happens:
- fuel cut on the rear fuel rail
- spark is maintained, which minimizes plug temperature loss and prevents fouling induced from incomplete combustion during cylinder re-activation. Sparking in air alone results in higher voltages than in a fuel-air mixture because of the higher insulation resistance. Thus, Honda used iridium-tipped spark plugs are used because of their high resistance to wear at high voltages.
- Intake / exhaust valves sealed on the out of service bank of cylinders (the rear, in this case, because the catalytic converter gets to remain at an optimal temp, and because the front bank gets the best cooling efficiency)
Sealing the valves cuts the inefficiency of pumping intake / exhaust out of idling cylinders (and improves FE in the process)
To improve the ergonomics, Honda also employs a noise-cancellation system through the audio speakers, because normally, an engine running on half it's designed capacity produces an annoying booming noise. The noise still persists, but by introducing a complementary tone at just the right frequency, the noise is 'cancelled', and you don't hear it (it still works if you have the radio off).
Honda also has this system in their upper-end trim on the Odyssey van, with the 3.5L V6. Given that the J30 and the J35 are Honda's V6 workhorses, I'd like to see this adapted to every V6 in every carline (Honda *and* Acura). Or at least make it an option in every carline. Only works well w/ V6 engines, though...Wayne reported that the Honda engineers tested it on I4s and found that it just wouldn't pass muster with consumers (not enough power on demand, fast enough).
Last edited by GreenAndBlue; 03-23-2005 at 05:42 PM. Reason: Correction
#16
03-23-2005, 05:49 PM
Great minds think alike, I always say... I was going to suggest an 'infolink' for VCM, given it's (hopefully) increased prominence, but forgot to ask. Thanks, Jason 
I also posted a correction to my post - spark is *not* cut, as I originally stated (some of my text for why it's not is from Hondanews.com);
FYI - anyone with a HAH who wants to know more about the engineering of the car (did you know that the ABS actually preloads the brakes when you're on a hill in auto-stop, for example ?) would do well to visit that site and grab the 'technical highlights' bulletins they posted there (I think there's 4 total; if people want them all posted here, I'll be glad to oblige)
I also posted a correction to my post - spark is *not* cut, as I originally stated (some of my text for why it's not is from Hondanews.com);
FYI - anyone with a HAH who wants to know more about the engineering of the car (did you know that the ABS actually preloads the brakes when you're on a hill in auto-stop, for example ?) would do well to visit that site and grab the 'technical highlights' bulletins they posted there (I think there's 4 total; if people want them all posted here, I'll be glad to oblige)
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