We are getting great gas mileage, 46.6 on first tank, and currently at 46.1 on the second tank. I have a couple of questions

1) The auto-stop feature doesn't work sometimes. For example today, on the first drive of the day, we would come to a stop light and the car seems like it attempts to auto-stop, shudders the engine a bit then continues to idle. It actually feels like the engine is about to stall, but then comes back to life. It did this for about 10 minutes of driving in 90 degree weather. How exactly do weather conditions, use of AC and engine warm-up relate to the functionality of the auto-stop?

2) I find it odd that the car autostops at about 5mph when coming to a stop. It almosts makes you feel that you lunge forward a bit because of the generator load-release.

We are very happy with the car, we are just trying to learn the quirks. We are going on a 35 mile drive later today, and we're going to take non-highway route (cruise control at 45mph). I'm trying to get that MPG up over 50 for the tank....

 

When you let off gas peddle auto-stop comes on at about 5 miles per hour, with light braking you should see 2-3 green bars, the electric motor is acting as a generator and brakes are not engaged. Generator/electric motor is slowing you down. As you apply more effort to brakes to stop the brake pads engage, the green charge bars increase to 4-7 bars. As long as stay on brakes the auto-stop is in affect. If you let off brakes gas engine starts go and auto-stop will not come on again until you get up to 8 miles per hour and stop again.

You must be in D not S for auto-stop to come in to play, the cars software must see coolant temp. up to normal, enough SOC and battery temp. with in the normal range. A/C, radio, lights etc. will run off battery while in auto stop.

Looks like your new HCHII is acting correctly....

Have fun and enjoy

Rick

 

You are pretty much on point with everything. I average around 45mpg but just recently hit 53 r/t on a 88 mile drive!! My first true leg of any length that got over 50! In regards to your concern about the "stall" feeling...that is how mine is and I consider it normal. If your A/C is on, and you hear that fan blowing on high, then typically the auto-stop doesn't engage as there is way too much stress with the A/C blowing for it to kick back to battery powered for cooling. This happens frequently for me when it's 90+ outside and I turn the A/C on. In about 10 mins or so, the cabin has begun to cool, battery pack is cooler, and the compressor doesn't have to work as hard to keep it cool inside.

You will also get used to the "lurch" feeling with auto-stop and learn to use it to your advantage. I tend to try to get auto-stop to kick in and ride with just enough pressure on the brake pedal to keep AS but also keep the momentum moving the car. This works well on downhill slopes, as you could imagine. Just be careful not to get up too much speed in AS then take your foot off the brake and kick the engine back on. it does NOT like this!

Glad you enjoy your car though! I love driving this car, and it's only been about a year and a half!

 

It's not because of the "generator", it's because the regenerative braking stops and there is a not-very-seamless transition to the mechanical brakes only.

What you feel is the loss of the regenerative braking, giving less brake force suddenly. I agree, it could be better, but you get used to it.

 

Yeah, I agree it could be more seamless. But its not a big deal. I'm happy getting 46 mpg.

BTW... It is a generator at that point.

 

I have been driving ours now for 1 week all city driving, I have noted the same characteristics, With the salesmen show and tell on the finer point of the hybrid they left the car idle, we got 200 miles on it but the MPG is at 38. Still very acceptable tank is a 1/2 and didn't have to fill the truck! One thing my salesman told me was not to hard brake, jack rabbit starts, keep under 65 MPH and no cruise control for the first 600 miles. We have following that suggestion. Though the past new cars I bought since the 70's it was drive it like your going to drive it, one excepting was my Audi was no hot rodding until the oil temp was over 60 C.

Have fun now garydan talk to you later on this discussions

 

Yeah, mine will shudder a little sometimes and then not autostop, but it always seems to be when the Auto AC is still trying to bring the temp down with high blower and crankin' on the compressor.

BTW, Autostop engages at 7 MPH and in stop n' go traffic, you have to get back up to 7 MPH for the autostop to re-engage.

I agree on the hills. There is a spot on the Interstate here that backs up every day and if I do it just right I can autostop, then coast in autostop down the hill for quite a distance before having to stop again. I think I've been up to 18 or 19 MPH in autostop.

I also try to do this in the parking lot at work.

Best,

 

How many bars of battery did you have? If you were low on charge, it won't auto-stop if you have the A/C on (I don't use the AC so I don't know where the cut off is).

Sometimes when I try to come to a stop smoothly, sometimes I lift off the brake pedal just a little bit at the end. This seems to send mixed messages to the car and sometimes causes auto-stop to not happen. If you have another lull like you described above, try braking a little hard at the end and see if that makes a difference.

For what it's worth, in 90 degree temps, you should be getting auto stop after about a mile of driving and it should happen as long as your battery is above 4 bars with the AC on.

 

True, and perhaps semantics, but this mode is generally referred to as "regenerative braking" so everyone is on the same page.

As for the autostop to "re-stop" in stop-and-go, I have found that you do not need to go over 7 mph for it to re-set. Most of the time, a brief creep and re-stop will be enough although it may take a couple of seconds for it to make sure you are stopped again.

 

Once everything is warmed up you do get one freebie auto-stop without having to go over the 7mph reset. In stop and go I try to let 2 car spaces (sometimes even 3) open up in front of me before I go and sometimes I just hit the 7mph reset for another auto-stop.