Sorry Kephra;

I meant to say "S".

This is what happens when one drives a Prius as well as the HCH-II.



Cheers & Happy new year;

MSantos

 

Oh, 'S'.

I didn't know about that, so I tried it this morning. I live at the top of a 3 mile 7% grade, and that worked pretty good.

I also noticed for the first time that my engine temp actually drops as I go down the hill. I had my block heater plugged in all night, and when I started the car, I had 4 bars on the temp guage. By the time I got out to the highway, I had 5; but by the time I got to the bottom of the hill, I lost two bars of heat, and only had 3. I'm going to have to try blocking off my grill.

 

When i switch to S, my rpms rev up past 2,000 is that wasting more gas, than just waiting for the car to warm up, then go into forced regen?

 

yes. S has very limited applications... I use it mainly as a forced brake without using the brakes when I go down steep inclines for example. S puts the car into a "S"econd set of gear ratios designed for more performance at the cost of more fuel.

 

Sadly, I did not get to verify that on the HCH-1 I had in the past.

However, I can say that the HCH-II does not consume "more" fuel when "S" is evoked for inducing engine braking.

For instance, when the gas engine is not fully warmed up, the fuel consumption is identical to the idling rate. Here's an example:

If engine temps are at

< 60C (140F) the fuel consumption rate is 1.2 L/H
> 60C but less than 70C (158F) the fuel consumption rate is 0.7 L/H
> 70C then the fuel consumption rate is 0.01-0.04 L/H which is technically zero.

So, by using the "S" to induce deceleration in an HCH-II, we can expect to do no worse than the fuel consumption rate we would experience when stopped at red light.

Cheers;

MSantos

 

I don't think there is a mode under braking that consumes more fuel. My example was to show when I use S, not that S alway uses more fuel.

 

Thanks MSantos for that info. But if the battery cold and the car doesn't want to do regen braking, wouldn't forcing the regen be bad for the battery pack?

 

No, because the BCM will always accept a charge as long as the battery module temperature is above -15C (5F). Of course, the batteries we have can only be charged at a low rate when the temperature is below 10C (50F), and the BCM takes care of administering the safe charge rate.

Second, just because the display indicates a sizable regeneration when switching to S, does not mean that the battery pack will actually receive the full charge. In cold days, particularly when the battery modules are cold, part of the regen is actually "discarded" and/or diverted for downstream use. The key is to get the cabin warm quickly enough by using a block heater and the battery temp will rise very fast in the first 2-5 minutes of the drive. This will allow for any "S" induced regen to be actually retained by the BCM sooner.

Cheers;

MSantos

 

On my 2008 HCHII the temperature gauge is a group of "blocks". Almost all the data points given in this thread, like the quote above, are in numbers (degrees F or C). Can anyone equate the "blocks" on my temperature gauge to numbers (i.e., each block is xx degrees F)?

 

Doug;

You can certainly make an approximation as to how each "block" corresponds to the actual temp values, but In my experience that approximation leaves much to be desired. In other words, I find the temp gauge on the HCH-II merely decorative and utterly useless.

Instead, I humbly recommend you get a Scangauge as it reveals far more information than just the engine coolant temp and far more accurately too.

Cheers;

MSantos