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My favorite feature of my HCH is the Auto Stop. It has made me a much calmer, more relaxed driver.

Occasionally it does not Auto Stop at lights. (Most times I understand why. Some I don't. I read the post and it still doesn't make sense sometimes, but that's not the issue here so please don't comment on that).

If I think it's going to be a long-ish stop, I'll manually turn the car off and restart it when the light changes.

There is a big difference in the behavior of the two starts. I asked my dealer if I was doing more harm then good to the car by doing that. They said no.

On older cars, it heard that they use more gas starting, then they do idling for about a minute.

So, my questions are....

1) Am I causing more wear, or potential other issues, by manually stopping and restarting?
2) Am I actually saving gas?

I can't speak for the HCH specifically, but it only takes about 5-10 seconds worth of idling to restart a fuel injected car. In the days of carberated engines 30 seconds or more was the break even point.

6 seconds as tested here: http://www.slate.com/id/2192187/

Cool article.
It still seems like there's a lot more going on when I manually start the car, but it's not really causing any issues, I'll keep doing it.

I hate Toyota (and I don't fit in a Prius anyway), but I would so much prefer the pure electric start off.

Hi Dana;

I think you got it with regards to the differences in behavior. The occasional forced auto-stop is a good thing and harmless in term of engine wear.

Yes, at the longest lights... powering the vehicle down is a good thing to do especially if your SOC is just So-so. However, if you use the forced auto stop too often, you'll also notice a few other things take place... such a weakening 12V battery and the others effects that tag along with it.
Like all other great and powerful techniques, balanced and strategic use is the key... especially if you plan on owning the car for a good while. ;)


Cheers;


MSantos

I didn't think there was much difference: starting via the key, vs autostop coming off. Both are using the Integrated Motor Assist, and to me they at least sound similar.

One thing that bugs me is the way the engine turns back on when you've rolled to an AutoStop at your destination (not intending to move the car any more), when you shift into Park. I adapted to this by turning the key off before shifting to Park, to avoid that start-up.

Mendel,

Me too. That bugs the heck out of me. Either the dealer told me, or I read somewhere that they did that so people wouldn't forget to take the key out of the ignition. You'd think the fact that they didn't have the key and couldn't lock the door would give them a clue.

Starting the car with the key seems to take it just a little bit longer and the engine seems to rev a little more (plus all the lights come on and all the systems have to reset).

Yes, at the longest lights... powering the vehicle down is a good thing to do especially if your SOC is just So-so. However, if you use the forced auto stop too often, you'll also notice a few other things take place... such a weakening 12V battery and the others effects that tag along with it. I can attest to this on my Honda Insight.

If your battery pack is going bad, a long autostop with battery pack and A/C fans on can easily prompt a recal.

My HCHII has 122,000 miles on it. Today I am in Phoenix for some work-related stuff. The car is still going into auto-stop even with the AC on. Outside temps are at 95F. Won't stay off through a long stop, but at least it is still doing its thing.
I have been told that at temps above 100F the auto stop won't work if the AC is on.

I wish Honda would not treat the working of the IMA like a state secret - the less I know - the more I worry. The more I know - the better I can treat the car.

I didn't think there was much difference: starting via the key, vs autostop coming off. Both are using the Integrated Motor Assist, and to me they at least sound similar.
...

Hi Mendel;

Yes, yes they sound similar (as they should above -25C) but there is a significant "functional" difference that affects a variety of things. For instance:

When you power the car OFF with the key you reset the IMA operational states. This affects a Regen cycle as well as the operational state of the PCM. As you may recall, the IMA Gen 4 has 5 states and when you "force auto stop" by turning it OFF with the key, you literally go back to Stage 1.
Powering the car ON with the key also means that it will be dwelling for approximately 10 seconds in a less fuel efficient state - as in - more fuel is being used at a faster rate. This will happen even if the car's engine is warm enough to be well above Stage 3.
Powering the car ON with the ignition key places far more stress on the 12V system than the resumption from AutoStop would. This is not a big deal if these forced stops are spread far enough apart, but do them frequently enough and the proverbial low charge "wrecking ball" will hit you.

As for powering down the car following an Autostop event, this is what we've been recommending:


Car enters autostop. Keep foot on the brake pedal.
Switch Transmission to N (optional *)
Turn Ignition key to OFF
Set parking brake
Switch transmission to P
Remove key from ignition, release foot from Brake pedal.
Many folks omit step 2 and it makes sense since the IMA system positions the CAM & STATOR and readies the CVT rather adequately... just before the ICE power down.


Cheers;

MSantos

...
I have been told that at temps above 100F the auto stop won't work if the AC is on.


To be accurate, it depends.

Autostop will continue to work as long as the demands on the climate control remain reasonable and the state of charge allows for the electric AC operation to continue.
The thing to remember here is that under normal circumstances, the HCH-II's AC scroll compressor starts in electric and is assisted by the gas engine when the conditions demand it.

Now, what is truly critical is the IPU temperature (which is directly dependent on the cabin temps) more so than the ambient temps. So even if the temps reach 110F the system should continue to function normally provided that we do OK in keeping the IPU happy.


Cheers;


MSantos

Seeing that you are in Winnepeg, and I am in Glendale, AZ it seems the right time to ask if you guys are going to get the Jets/Coyotes back? Everyone here thinks they are going back home.

Ahhh... see, I am not a big Hockey fan but I would wager that not many folks want the Jets back. Not that the Moose are doing great, its just that some folks are OK with leaving the past where it belongs. :)

Cheers

MSantos