Sitting on the freeway, traffic inching, stopping, inching for an hour, I sure wished the Insight would crawl along on electric motor only instead of autostopping at each lurch....
Those of you who know the electronics well?
Would it possible to add a momentary pushbutton (on the gearshift knob) that when held in would keep fuel from getting into the gas engine and also fool the IMA into thinking the gas motor had started? Theoretically autostop would then inch the Insight along on the electric motor only (100% assist). When traffic merits faster speed the driver simply releases the crawl button and autostop starts the gas engine as normal.
This seems like an ideal use of the Insight's electric motor.
If there was a way to declutch the IMA from the crankshaft it would be a great idea. As it is the ICE puts a huge drag on the IMA motor.
A fractional horsepower in hub electric motor in one or more of the rear wheels could work wonders. If it was rigged to take over the throttle from the main engine when the gear shift was in neutral ( drive by wire) we could have have the ultimate plug in hybrid design TODAY! (150 MPG)
Now if I could just find my lost magic techno wand.
__________________
Kip Munro
The laws of physics don't need changing, but rather our attitude and values. 72.8 LMPG
The primary problem is the the ICE (Internal Combustion Engine) is coupled to the IMA motor (electric motor). So any electric only mode also requires that the ICE is turned over too. Yes, you could force the injectors "off" to eliminate any fuel consumption, but the increased drag is still there.
And remember _ALL_ of the IMA battery power ultimately comes from gasoline. Yes you recover otherwise "wasted" energy on regenerative braking, but the power getting to speed came from gasoline. So too much electric consumption will result in a forced charge and _reduce_ or eliminate the gains from more agressive IMA motor use in a "creep" mode (the ICE's friction again).
There is an available "hack" to allow more IMA control. And we're still smarter than any computer. MPG gains can be realized from more agressive IMA usage in normal traffic. See:
OK thanks, I figured this must have been thought of before. If I understand the Civic's ICE, they can open the valves on 3 of 4 cylinders on demand, which would of course cut way down on the parasitic losses.
I remember VW had an autostop model in Eurpoe (in the 80s?) that de-clutched on both sides of the flywheel and used the flywheel's kinetic energy to restart the ICE when the light went green. It would be a major alteration, but if a second 60mm electric motor were inserted on the driven side of the Insight's clutch, then you could clutch-out the ICE and run on that second electric.
Yes the new Civic has an "all electric " mode. Personally I think it was advertised as such to respond to Synergy drive worshippers who insist that a car is not a real hybrid unless it can run on electricity only, while conveniently ignoring the fact that Synergy drive cars cannot run on gasoline only.
The Civic achieves this by closing the valves so that the pistons act like almost loss less springs. This does allow more efficient regeneration of electricity when slowing down and braking.
Yessir, a second IMA motor on the clutch side would work just fine and would give noticably quicker accelleration as well. I wouldn't want to try it unless I owned a well equipped machine shop. Also, the second motor need not be that big.
__________________
Kip Munro
The laws of physics don't need changing, but rather our attitude and values. 72.8 LMPG
And remember _ALL_ of the IMA battery power ultimately comes from gasoline. Yes you recover otherwise "wasted" energy on regenerative braking, but the power getting to speed came from gasoline. So too much electric consumption will result in a forced charge and _reduce_ or eliminate the gains from more agressive IMA motor use in a "creep" mode (the ICE's friction again).
...
But _ultimate_ MPG is still derived from little or no use of charge or assist, when traffic will allow.
BUT, there is something else that is being ignored by considering MPG alone. stopping and starting of the ICE to go less than 5 ft numerous times, as would happen in stop and go traffic, especially on a highway/interstate backup or wreck would cause much more pollution (imho) that has a worse effect than losing a few mpg in a regeneration, because when you are in regen to make up for using an ev crawl, you are traveling at a high rate of speed, making less pollution per distance traveled than stop and go.
And I am not sure that regen would lower mpg more than stop and go as well. I have had many experiences when catching multiple red lights with slow take offs and gliding that had a more detrimental effect on my mpg than a forced regen. Maybe because it is a bit hilly in the traffic areas. I have had 100+ mpg 20 mile trips, and have had the unfortunate experience of around 30 mpg stop and go 10 mile trips, where nothing I tried to do could help (all of this in a HCH I CVT). I feel an ev glide 'may' have helped in that situation ... since I don't like the idea of FAS coasting ... just don't feel secure doing it with an auto tranny.
Please feel free to correct me if I am wrong.
I also feel sometimes we need to look at the bigger picture and not focus on numbers alone (the highest possible LMPG). I am not saying to drive like it doesn't matter, but use our brains a bit more than our passion for competition or obsession with the number. I personally try to keep the instant guage in my vision and maximize it the best I can, but I won't forego using A/C (100+F outside) and sweat to death in my vehicular investment that is a fair percentage of the cost of a house. For some that is worth it though, and I commend their efforts and support their decision 100%.
I think a crawl option would be great if they gave it to us, but hacking a car is a brave move to achieve such a wonderful thing. I may consider it in the future if I ever catch my dream Insight or maybe two, one stock cvt, one modded 5 spd.
I second the thought that an EV "crawl" mode would be more efficient than even running in first gear at constant 5mph, let alone stop and go!
A gasoline engine is least efficient at low load. Pumping losses are large here, also, just the general friction load of the engine turning is large compared to the tiny amount of power needed to keep the car rolling. So yes, it would be much better to use electricity for this, and then recharge at higher engine load and better efficiency. That's what the whole hybrid idea is about!
Quote:
Originally Posted by bluesesshomaru17
I also feel sometimes we need to look at the bigger picture
The bigger picture is this: Even if you go a whole mile at crawl speed and only 25mpg, it's only 0.04 gallons of fuel. So if that's one mile out of your 50 mile commute, it would lower overall mileage from let's say 70mpg to 66... Also, the Hummers next to you probably get 1 or 2 mpg crawling, if they're lucky!
Then of course there is the E-Wheel, where one can push the Insight under pure electric for 30-40 miles. I was stuck in an accident backup situation several months ago on I-95 near Stamford CT. The stop and go for more than an hour, and over 10 miles was accomplished with no gasoline use at all. All around me there was idling tractor trailers, suv's, and regular cars burning thousands of gallons for that single event. http://www.99mpg.com/ProjectCars/mikesinsight/
While hanging a 5th wheel on an Insight is not something that is practicle for most people, If the rear wheels of any front wheel drive car could have electric hubs, think of all the gas we could save in city and other stop and go traffic.
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How hard to add "crawl mode"?
