I think your suggestion of having it detect it on a downhill is good. I'd take it a step further and have it so that the regen only automatically kicks in if the car is on enough of a decline to actually accelerate, and only enough that it keeps the car at it's present speed. That way, it would be a built in speed-controller for declines. Tapping on the gas pedal should kill the regen but still not use any fuel.

Perhaps a "brake" switch similar to the Prius could allow for optional max regen when coasting as well.

As it is on my '03, on gradual downhills in town I only have a choice between regen eating up all my speed, or coasting in neutral... although, on the Hybrid Civic, idling seems to use very minimal fuel when the engine is warm. If I'm in a situation where I woujld need to use gas even to cancel out the braking effect of the spinning engine, neutral is more economical. I'd imagine though that on the '06 with cylinder shutoff, engine braking would be much less than even the '03, enough so to make it superior to neutral at most speeds.

How do the pre-06 HCH's work? Does full regen kick in as soon as you take your foot off the gas? Or when you apply any amount of brake pressure? I have no experience in any hybrid other than the 06HCH, so I'm curious.

All the Hondas (Insight, HCH, and HAH) until now have had substantial regen kick in as soon as pressure is released from the gas. The car has to go into neutral to prevent regen during a coast. Apparently even the HCH II does this, but not to the same degree, and it can be defeated with a simple twitch of the foot, no shifting required. That's the exciting part- Honda is making it simpler and easier to run optimally without all the tricks that Xcel and others are referring to.

Hi NASAgineer:
___I think the following may help come up with my interpretation of what I would like to see vs. what you are actually experiencing as far as SoC depletion and acceleration rates … Your view point is far more accurate then mine in regards to the HCH-II of course … “Tbaleno takes the Gloves Off” w/ his CVT based HCH - P&G ;-)

___As CGameProgrammer mentioned, the HCH-II doesn’t have a leanburn mode but you have an atkinsonized intake. This is the trade off for low load drivers in the HCH-I vs. the HCH-II. You have to get some of that tire rolling resistance (higher pressure in the tires) and mechanical rotational friction (Mobil1 0W-20 vs. the moly laydened goo in her now ) beat out of her to really tell what she is worth in the steady speed cruise but what you are doing so far is great start!

___Let me know what kind of tires she is equipped with. Most tire manufacturers have a MAX sidewall of 44 #’s with some of the HCH-I’s shod with some 51 #’ers. I run all my automobiles with Michelin’s, GY’s, Bridgestone’s, and Continental’s at 50 + except in the MDX (35 #’s MAX sidewall on the Michelin X-Terrains) and they go to 37 as that is the wife’s car.

___And back on track possibly? I would not use your new found EV mode for holding a steady speed but for slow bleed off w/ no regen and maybe a slight amount of Assist to get you over the next slight hill and such. Maintaining a steady cruise off a .5kWh usable pack is really pushing her hard and over time, this is not a good thing no matter how much more protection Honda has designed into her from previous gen IMA systems. I can tell you from a thousand reads on the subject that Honda is the loosest hybrid manufacturer in regards to pack protection constraints and even on the CVT based HCH-I’s, it leaves something to be desired. Secondly, learn to DWL where possible. Honda has given you a great tool and with the DWL technique, you should be able to maintain longer glides/coasts and your FE should improve mightily even where you would think it would not work in the least.

___GoNavy, Honda certainly is approaching nirvana even with IMA’s limitations as NASAgineer is explaining in excellent detail to all of us. The ICE-Off neutral in any car is indeed illegal in some locales yet Honda got away with 19 mph and below in the Insight 5-speed w/ Clutch in (she is running in neutral w/ clutch engaged even while in gear) and lower speed AS’s in the HCH-I and AH. The Prius II is in a pure EV or Glide mode depending on throttle input and if the interlocks are made up for ICE-Off on a coast down from 40 mph and below so it is not technically ever in neutral. That was a great explanation on a control volume (intake/exhaust valves and piston cycle as a stand alone) in the HCH-II’s valves closed ops mode. I still wish IMA was on the outside vs. inside of the CVT so that you wouldn’t have to spin that crank, cam shaft even though the valves are closed, drive those pistons up and down, and keep that tranny fully engaged is all

___As far as all the tricks, you bet I would like to get rid of them! It will not be long and all cars will be designed with these tricks built in and its about ****ed time The FEH, Prius II, and now the HCH-II are getting very close to where they need to be. Another generation of HSD and IMA and we should see optimization … I can only hope?

___Good Luck

___Wayne R. Gerdes

The stock tires are Dunlop SP37 A/S. Size P165-60-15.

Does anyone know? Michelin have (Low-Rolling-Resistance-Tires) in that size?

Terry

Hi CGameProgrammer:

___I cannot find a single thing on those Dunlops anywhere? I found a place that sells the SP37’s at 0% used off of other vehicles for an extremely attractive price but TireRack and Dunlop itself has no specs for them listed that I can find? Can you read the MAX Sidewall Pressure off the sidewalls for us? Since you are looking at them that closely, would you mind posting the Treadwear, Traction, and Temperature ratings off the sidewall as well?

___Thanks in advance.

___Wayne R. Gerdes

You know, I'm now seeing people echo the statement "no lean-burn for the new HCH" - but I saw on a website referenced by tigerhonaker in this forum a few weeks ago that the HCH-II did retain lean-burn (can't find it now, however). I believe that site was the hondanews.com site.

When I went there just now... http://hondanews.com/CatID2013?mid=2...41801&mime=asc

...they're referencing i-DSI , I believe - and if so, isn't that like a "super lean-burn", compared to the old lean-burn setup ? (start reading about halfway down the page for the HCH info)

Also - I see reference to the 'atkinsonized intake'. Can someone explain how that conclusion was reached ? I'm thinking this is still a 'traditional' otto-cycle engine.

Great post, Wayne! That explains many of the questions I had about your P&G technique. I didn't understand how I could pulse with assist and cancel out regen without draining the pack, but now I see that you expect forced charging to kick in. Pulsing without assist gives me a very slow rate of acceleration.

Is this better than the 0W-20 that Honda dealers sell?

Reading from the side of the tire:

"Bridgestone Insignia SE 200"
"P195/65R15"

"Max load 1279 lbs. at 44 PSI max pressure"

but it also says:

"Never exceed 40 PSI to seat beads"

treadwear 380
traction B
temperature B

Dunlop lists the SP40 A/S on their website so I guess that replaces the 37s.

Anyway I read all the information on the tire. Well for one I was wrong about one measurement (width?); it's 65, not 60. Anyway here are the stats:

Max pressure: 44 PSI
Max load: 1279 lbs
Treadwear rating: 320
Traction rating: A
Temperature rating: B