Any enterprising person want to disable IMA?
#11
12-13-2005, 02:38 PM
Re: Any enterprising person want to disable IMA?
A little more information on S-mode: when accelerating from a stop, you kind of need to let it use 4 bars of assist, or at least I didn't have the patience to try to accelerate without any... but from 50mph on, it was easy to accelerate with literally no assist at all, gaining about 2 mph every second, so I was at 80 in no time. Actually that was going uphill (0-80 totally uphill, though it started to level off near the end), so on level roads it should be better.
The engine was at about 4500 rpm. It rode surprisingly smoothly though; in fact it felt more smooth than with assist, but it's possible that's just because the sound wasn't as high.
The engine was at about 4500 rpm. It rode surprisingly smoothly though; in fact it felt more smooth than with assist, but it's possible that's just because the sound wasn't as high.
#12
12-13-2005, 02:42 PM
Re: Any enterprising person want to disable IMA?
Originally Posted by CGameProgrammer
A little more information on S-mode: when accelerating from a stop, you kind of need to let it use 4 bars of assist, or at least I didn't have the patience to try to accelerate without any... but from 50mph on, it was easy to accelerate with literally no assist at all, gaining about 2 mph every second, so I was at 80 in no time. Actually that was going uphill (0-80 totally uphill, though it started to level off near the end), so on level roads it should be better.
The engine was at about 4500 rpm. It rode surprisingly smoothly though; in fact it felt more smooth than with assist, but it's possible that's just because the sound wasn't as high.
The engine was at about 4500 rpm. It rode surprisingly smoothly though; in fact it felt more smooth than with assist, but it's possible that's just because the sound wasn't as high.
#13
12-13-2005, 02:43 PM
Re: Any enterprising person want to disable IMA?
NASA: I too doubt a single bar has much impact; in fact I doubt it's even 25% of the regeneration of 4 bars... I suspect it's more exponential than linear, but who knows. But when I allow the car to use assist, I frequently find myself at 3-5 charge bars remaining by the time I'm up to speed. It depends on hills, traffic, and its level before getting onto the highway. Then it punishes me with regeneration and doesn't let up for a long time.
#14
12-13-2005, 02:47 PM
Re: Any enterprising person want to disable IMA?
Originally Posted by Archslater
So you leave it in "second gear" (S) while on the highway, or just while accelerating? Doesn't the corresponding higher rpm's kill your FE?
For a 5-mile highway jaunt, I would not use S-mode except experimentally. For a 20+ mile trip, I would.
#15
12-13-2005, 04:24 PM
Re: Any enterprising person want to disable IMA?
Originally Posted by CGameProgrammer
Well since both regen and mileage are dependent on gas pedal pressure, it's hard to measure the exact difference since any any given time either regen is on or it's off, I can never toggle it while keeping everything else constant. But when I've driven on the highway without regen, I definitely appear to get higher mileage than with it on, and that's logical, isn't it? I can definitely feel when regeneration is on, even a little. It's alot more enjoyable when the car just glides.
But guess what? I figured out a way around it using 'S' mode! I'll post more about it when I have a chance to collect more data, but with S it's easy to accelerate using just a high-revving ICE and little to no assist. I was able to drive on the highway at 80 mph with a completely full battery; when I got to the exit, the friction brakes were mostly used with barely any regeneration since the battery was full.
Unfortunately I don't have very useful MPG figures. I had 14 miles of 34 mpg on the trip meter when I began a 20-mile highway trip that brought it to 41 mpg going mostly 80 mph (some traffic made it 70-80). But that had a bunch of downhills. On the way back, with a reset trip meter, I got 40 mpg from 0mph to 0mph, but not only was it mostly uphill but there was a headwind... weather.com says 12 mph but it felt like more... anyway hopefully sometime I can do a more fair test and compare the two driving strategies.
Clearly S is less fuel-efficient in the short term but over a decent-length highway drive like the one I did, it definitely helped alot.
But guess what? I figured out a way around it using 'S' mode! I'll post more about it when I have a chance to collect more data, but with S it's easy to accelerate using just a high-revving ICE and little to no assist. I was able to drive on the highway at 80 mph with a completely full battery; when I got to the exit, the friction brakes were mostly used with barely any regeneration since the battery was full.
Unfortunately I don't have very useful MPG figures. I had 14 miles of 34 mpg on the trip meter when I began a 20-mile highway trip that brought it to 41 mpg going mostly 80 mph (some traffic made it 70-80). But that had a bunch of downhills. On the way back, with a reset trip meter, I got 40 mpg from 0mph to 0mph, but not only was it mostly uphill but there was a headwind... weather.com says 12 mph but it felt like more... anyway hopefully sometime I can do a more fair test and compare the two driving strategies.
Clearly S is less fuel-efficient in the short term but over a decent-length highway drive like the one I did, it definitely helped alot.
I feel the same way that you do about the Regen to to some extent. It def. slows me down on the highway lossing precious MPG. However, in the long run I think you may be doing more damage to your car by using the "S" mode. "S" mode is second gear, which is not designed to be ran at highway speeds. I don't know about the CVT that much but in a regular transmission Second is a lower gear so you will use less IMA do to more power being sent from the engine. This over long run will give you lower FE becuse "D" is higher gear for better FE at highway speeds. Also, when driving in second gear at highway speed your engine is running at much higher RPM'S to keep up to speed. This will put added unwanted wear on you drivetrain, ie ICE and CVT. This may not be worth the added FE in the short term. I have however found that while coasting if I ever so lightly press on the accelerator as if in EV mode regen will stop, I will continue to coast without losing speed and my MPG will be top out it 100. Almost no fuel consumption if any is taking place. The only down side to this is that may battery charge doesn't stay as full as it has been in the past due to not being recharged.
#16
12-13-2005, 04:37 PM
Re: Any enterprising person want to disable IMA?
Originally Posted by Adam_HybridCivic
However, in the long run I think you may be doing more damage to your car by using the "S" mode. "S" mode is second gear, which is not designed to be ran at highway speeds.
Also, when driving in second gear at highway speed your engine is running at much higher RPM'S to keep up to speed.
This will put added unwanted wear on you drivetrain, ie ICE and CVT.
I have however found that while coasting if I ever so lightly press on the accelerator as if in EV mode regen will stop, I will continue to coast without losing speed and my MPG will be top out it 100.
#17
12-13-2005, 04:53 PM
Re: Any enterprising person want to disable IMA?
Originally Posted by CGameProgrammer
There is no second gear; it's a CVT. All 'S' mode does is tweak the CVT ratio so the engine runs at a higher speed than it otherwise would, generating more power. And apparently it uses much less assist but does use alot more regeneration if you were to coast with it on. It is perfectly healthy; the engine was only at a 4500 rpm going up to 80 mph, which I've seen it do many times in D mode anyway. Plus, the engine automatically runs at a higher ratio when it's cold in order to help heat it up more quickly; check the manual.
I don't cruise in S, I only accelerate from 0 to highway speed in S, then switch to D. It helps alot in the long term.
4000 rpm will not damage the engine.
I do that too but coasting is not the issue; driving is.
I don't cruise in S, I only accelerate from 0 to highway speed in S, then switch to D. It helps alot in the long term.
4000 rpm will not damage the engine.
I do that too but coasting is not the issue; driving is.
"Selecting Second (Gear) shifts the transmission into a lower range of ratios for better acceleration and increase engine braking..." S does stand for second gear. CVT's do still have gears like a regular transmission, I do know that much. Anyway, accelerating to highway speeds in S and then switching to D is much better then what I previously thought. I however, will not preform that on my car per I have seen first hand what that type of driving technique will to to a drivetrain. I didn't realize that you are having regen will driving and not coasting. From what I recall I do not have that problem.
#18
12-13-2005, 05:02 PM
Re: Any enterprising person want to disable IMA?
Originally Posted by Adam_HybridCivic
According to the 2006 Hybrid owners manual PG. 168 (S) SECOND,
"Selecting Second (Gear) shifts the transmission into a lower range of ratios for better acceleration and increase engine braking..."
"Selecting Second (Gear) shifts the transmission into a lower range of ratios for better acceleration and increase engine braking..."
S does stand for second gear. CVT's do still have gears like a regular transmission, I do know that much.
I think you picture the CVT as merely smoothly shifting from one gear to another. That's not what it does; there are no distinct gears. Well except for the reverse gear. That's why you can accelerate while keeping the engine at a fixed RPM, or even letting it decelerate while the car accelerates.
Last edited by CGameProgrammer; 12-13-2005 at 05:07 PM.
#19
12-13-2005, 05:06 PM
Re: Any enterpriWithout the key in IG-III, IMA shouldsing person want to disable IMA?
Originally Posted by Adam_HybridCivic
S does stand for second gear. CVT's do still have gears like a regular transmission, I do know that much.
#20
12-13-2005, 05:20 PM
Re: Any enterprising person want to disable IMA?
CGame, Nasa, I understand that the CVT does not have an acutal set of gears like a manual or automatic transmission but it has a set of pullys which make up a gear range and not a set gear ratio. I sorry was was not technical enoguh. However, Second is still a lower "gear" range which can be subject to damage at higher speeds. Also with this being a CVT and using bands to move the pullys I would be more worry about damaging/ breaking a band that drives the pullys than damaging a metal gear in a regular auto/manual transmission. A CVT is much more expensive to work on or replace and I don't think that will be one think covered under warranty...unless they don't figure out what you were doing. Either way, its your choice what you guys decide to do.
