Anyone else giving up the MPG battle?

[GICU812]

When I got my insight in late July, it took me a bit to learn the tricks but I eventually got to where at the end of my 51 mile morning commute, I'd just top it off at 70MPG for the trip. Going home was a little less, probably because I was in a hurry

Well this morning I managed to top off at 57 MPG. There was a stark drop off a couple of weeks ago where the mileage just disappeared. Colder weather? winter gas? I dont know, but where as I could easily drop into "the zone" and cruise at 70-75MPG, I now find it hard to hit 60. I've often just said the heck with it and ran as fast as I wanted, only to find that im going 15 MPH faster at a cost of only a couple MPG.

Heck the other day I was going 65MPH on a slight downhill at only 60MPG and LOOSING SPEED!

I know one problem im having is with the stupid IMA. It starts background charging at 2 bars below top SOC, and pulls the equivellant of 5 bars charge until its been on 1 bar from top SOC for a while. This absolutely slaughters my MPG, because to try to keep the car moving at 65 I keep dipping into assist, then the hidden charge drags me down, and I dip into assist. I get mid 50's best when this is going on. I know this for a fact because I have an ossiclloscope on the CMDPWR signal and can see what its doing with the IMA. Ticked me off to the point that I shut the engine down and coasted while I reached back there and flipped the breaker off, just so I could get it to stop charging, not for mileage, but because I was tired of fighting the gas just to keep highway speed.

I mean what is the point in having a Kenetic Energy storage system if the damn controller charges constantly to keep it at top charge? I cant get anything from regen, because by the time I get to stopping, the battery is full. I literally cant get the charge below 2 bars from top without it kicking in a hidden charge of 5 bars regen.


AAHHHH!!!!!

So this morning I said the heck with it, and still got 57MPG, a hair below my recent bests. Im thinking about just putting tape over the MPG guage until next spring.

[Delta Flyer]

Accept the fact the weather is cooler....consider putting cardboard over the radiator to warm up the engine quicker.

More of a concern is the SoC problem - might want to get it checked, but I like what you did - a forced autostop is advanced hypermiling to get beyond 70mpg

[GICU812]

Well I keep it in the garage at night, and its not so much about warm up, as I drive 50 miles, it gets to temp at a decent time, stays there the whole time while im still getting rotten mileage.

Unfortunately, cardboard over the radiator won't help it warm up faster, the thermostat stays closed until it hits operating tempature, so there is nothing flowing through the radiator until the engine hits temp (what is it with these 195*?). It would block some air from blowing on the engine itself, through the radiator, but I wouldnt think that would be a signifigant change.

From what I understand, this is normal IMA programming, I beileve this car has had the MCM update, I have a reciept where it was brought in to replace one of the control modules under a "recall"

I plan to change this IMA operation, im just working out the kinks in m controllers to talk to the MCM. At this point, Id almost say it would be more beneficial for me to just gut the system... Makes me wonder at least. I know the main reason I cant hit "the zone" half the time anymore is because its always charging. I wonder if it was like this during the summer, but I think so, as I remember a while into the trip my mileage would improve. I thought it was the fluids coming up to temp, allong with me not messing with the throttle as much, now I know. Now it doesnt stop charging usually until after 25 miles.

[atlaw4u]

Also, consider doing the warm-air modification if you have not already.

[flymuck]

Gas may be an issue -- not just winter vs. summer, but brands may make a difference. Do you use the same brand every time? I just filled up my MT Insight -- it's a rare occurrence (about every 3-4 weeks). I had gotten 64.6 MPG on the last tank, filled with Chevron gas. This tank, I've so far only been getting about 54.7 MPG, filled with Shell gas. Maybe it's a difference between the winter and summer gas, but I'm also wondering if the brand ends up being really, really important.

-fly

[GICU812]

This setup actually works in much the same way as MIMA. I've looked over Mike's site, and in fact he has given me a good bit of advice over email. The advantage of my system will be that its much cheaper, and mostly I can change and modify it at will. Though he freely discloses the source code, so you could actually tweak his as well, I prefer to learn\do things myself, and im more comfortable with the code for my microcontroller. For starters Im just going to enable manual control, so I can turn off the stupid forced charging, then I'll work on cruise control using the electric motor to maintain a set MPG, and some other ideas.



Im thinking about the hot air mod. I'd like to build a capsule around the cat that I can hook onto one side, and put holes in the other, so it actually has to draw the air over the cat, heating it further. If I wasnt so hesitant to hurt the cat, Id seriosuly consider welding heat sinks to it too. But then you have to worry about over cooling the cat, welding holes in it, and well thats a whole 'nother project.

[GICU812]

Originally Posted by flymuck

Gas may be an issue -- not just winter vs. summer, but brands may make a difference. Do you use the same brand every time? I just filled up my MT Insight -- it's a rare occurrence (about every 3-4 weeks). I had gotten 64.6 MPG on the last tank, filled with Chevron gas. This tank, I've so far only been getting about 54.7 MPG, filled with Shell gas. Maybe it's a difference between the winter and summer gas, but I'm also wondering if the brand ends up being really, really important.

-fly

I was hoping that too, but its been the same for the last 3 tanks or so (I do a tank a week, which is a LOT of driving in an Insight )

Its a 5spd btw.

I last time I got Marathon, before that I think it was BP, before that it might have been speedy or something.

The other thing to watch for is when you get your gas. If you happen to get to the station when there is a filling truck there, go elsewhere. Filling the underground tanks stirs up the layer of water that the gas floats on, while they try to keep it down, you can never get it out, as more collects, anyway, that gets stired into the gas when they fill and you're likely to get a bit in your tank if you fill immediately after they do.

I'll try getting gas at some of the stations I did when I know I was getting good mileage.

[flymuck]

Honda has "preferred providers" for gas for the cars they make -- I know Chevron is one of them (I thought Shell was too!). I think it's on Honda's website somewhere (no time to look now). I would try your next tank with a preferred provider's gas. I find that it's worth the extra $$ (Chevron is $.20/gal more expensive than the Shell station I went to), but for the mpg, it's worth it -- if'n it actually makes a difference. Good luck! Let us know!

Edit: it's called "Top Tier Detergent" gasoline, and it's made by Chevron, Shell, Phillips 66, and others (not listed on the page I found). Maybe there's something not right about the Shell station that is so cheap...

[james]

"Unfortunately, cardboard over the radiator won't help it warm up faster, the thermostat stays closed until it hits operating tempature, so there is nothing flowing through the radiator until the engine hits temp..."

That's not entirely true. Most thermostats (though I've never taken the Insight's out to check) have a small bypass, so there's always some coolant flow. The radiator block could also block some airflow. Whatever the reason, the radiator block does make the engine warm up faster, and keeps it warmer on long downhills.

[joecvt]

It blocks a lot of cold air coming into the car that would normally cool down the engine while it is heating up. It also helps keep the engine closer to summer time temps.

JoeCVT - Just your average CVT owner