I have been driving my HCH 2007 for 2 months. Now that it is getting cold in Rochester NY 5-20 degrees F, I noticed that autostop infrequently kicks in. It hit me that the ICE needs to be running to keep the temperature at the thermastat setting. So now I keep the heat on when I first get going (first 2 miles of a 6 mile commute), then I turn off the heat and the autostop kicks in at all the stops and lights. The car stays warm for the rest of the ride. Also you need not reset the climate control with the auto button, just turn the fan control **** on the right and the previous mode will be restored. You can run the heat again at any time as long as it is off when you come to a stop.

 

Whether you have the heat on or not it shouldn't matter. All that determines if the vehicle goes into autostop is whether or not the engine is up to temp. By running the heater you are drawing heat away form the engine, thus cooling it slightly. With outside temps very low where u live this might be causing the engine to cool down too much causing the car to not go into auto stop. Try using a lower temp setting and make sure the defroster isn't on. I have no problem with my 06 going into auto stop with the temp set around 70-75 constantly during winter months.

 

It has gotten REAL cold in the Chicago area lately (-6 F this morning).
I know that my mileage suffers greatly in the cold, in part because Auto Stop takes a lot longer to kick in (needs to get engine up to temperature first) and in part because when the heat cools off enough, the engine will kick on again (I presume to warm up the car).

Once the car gets up to temp, my autostop works fine...kicking in at stop lights, etc. Even in very cold weather.....but if I sit too long while in auto stop, I find that the ICE will refire just to keep the driver area warm (based on the setting on the heater).

I guess in this case, turning the heat off would be beneficial....but somewhere along the line I had to ask myself...
"Is it really worth driving in 100 F heat with no A/C, or driving in -6 F cold without heat? Should I really drive 50 mph on the interstate, instead of 65?"
My answer is that the HCH II is a great little car, that gets great mileage compared to just about any other vehicle out there. Even if I do use the A/C or the heat, or cruise a little faster than optimal for FE, I am still getting great mileage and doing something good for the environment. I don't understand the people on this forum that won't drive their hybrid in the rain or snow because it has a negative impact on their FE.

Sure I like to see my FE as high as possible, but I still want to use the car...even when the weather is not perfect, and I want to enjoy driving the car...even if it means a lower FE.

 

Greg, I quite agree ... enjoy your car. Don't torture yourself. I think most of us feel similarly. There are some extreme MPG mongerers (meant in a nice way ), that will take extreme measures to get great MPG, but most of us just drive our cars with a little more interest towards fuel economy than we did before, and we're doing it in a car that gets great MPG. And that's a giant step in the right direction!

 

Well, there's a little more to it than that. The car is also trying to control the SOC. If this were not the case, then autostop wouldn't care in summer if you ran the A/C or not - it would autostop just because the engine is up to temp. Engine temp is one important variable, but not the only one.

I too have noticed that I can get the car to go into autostop by turning the heat down, but not always. I suspect that it has to do with where the car is trying to maintain SOC. I've noticed that somewhere between 20 and 30 deg. F, the car begins forcing the minimum number of bars that it is happy with from about 4 to about 7. I suspect this is to help the battery because it will lose power when parked in cold temps, and if it maintained SOC at 4 bars when it is very cold, you might park it at night with 4 bars and wake up in the morning with 2 or 3. The car always tries to maintain at least 4 bars to protect the battery, regardless.

 

I had to leave my HCH II outside last night and it got down to -10F (at least that was the temp when I went out to start it this morning....)

It was the first time that the car used the "traditional" starter...I had read that this could happen, but this is the first time I experienced it. Instead of the customary "quick" engine spin, it sounded a lot like a traditional ICE. I even had to give it some gas to get it to fire.

But, once running and warm (I drive about an hour to work), the Autostop worked fine. It certainly takes longer to get the enfgine hot, but I have found that once it is warm, I go into Autostop regardless of the outside temperature. Occasionally if I get caught by a train and stay in autostop for an extended period of time, the ICE will refire (I assume to keep the engine temp up to keep the heater warm (I generally leave the heater at 68F in the winter).

 

The fan needs to be in a lower speed (according to the manual). And the battery pack has to be within some temperature range, so as NOT to harm the pack when using juice from it. Or sending juice to it. (There are times your battery pack will NOT charge, even though you know it should. This is likely due to temperature of the pack.) Sometimes, it IS a mystery, though.