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Well, I thought was doing well breaking in my 2009 HCH-II and working up to ~52 MPG using mostly E10 gasohol in mixed driving to work and back. Suddenly, it has gotten much worse, I was only able to do about 46 MPG today. It is hot here (St. Louis, MO) but I do park in my garage at home and a covered garage at work, so the car doesn't sit and roast in the sun. I use the AC lightly, usually set the inside temp around 78F.

This is really bugging me. My 2008 HCH-II that got wrecked was up to 56 MPG at 3300 miles, when it got totalled. I now have 6000 miles on this 2009, and have never gotten over 52 MPG on it (tank average). Is this all from the AC use, or just the heat on the hybrid system? Summer gas formula? I definitely have not seen an SoC recal, although I have seen the SoC drop to 4 bars now and then.

Jon

What about tire pressure? It seems to make a big difference in mileage in my HCHII. I usually make sure I have at least 37-39PSI per tire.

I had a nail in my back tire and the pressure was down to 25PSI, and my mileage was lower for a few weeks

I use the AC lightly, usually set the inside temp around 78F...

Did you just recently start using the AC?

On many vehicles, it doesn't matter what you set the temp or other settings at. If the AC is on, the compressor is on (and that is the big drain on FE).

The temp is adjusted by adding heat to that cooled air. It's much more efficient to manually cycle the AC instead of letting the lazy computer do it.

Hi Jon;

When it gets hot, the mileage goes down for sure. The question is by how much and whether something can be done about it. It looks like you are doing many things right already but there are few more that may also be up your alley. For instance:

- Take the tire pressures up a bit more.
- Have a look here just in case: "HCH-2 AC tips" (http://www.cleanmpg.com/forums/showthread.php?t=14151)
- Wheel alignment!!!!

On the subject of wheel alignments: I always have the dealer perform a wheel alignment at the time of purchase on any vehicle shipped from Japan. No exceptions for me and I always recommend new owners ask for the same.
In every single instance, correctable deviations were found and handled before I drove the car off the dealer's lot. I am definitely not joking and I suspect the boat anchor you are dragging may be due in small part to that. I hope I am wrong this time.

Funny thing is that some folks have told me the minor skin/styling changes that were applied to the 2009 had a slight impact on the vehicle aero-dynamics and FE compared to the previous years. I have not verified that in the 2009's I have driven.... mainly because I never take them to higher speeds anyway!? What speeds to you usually drive at?

Cheers;

MSantos

- Have a look here just in case: "HCH-2 AC tips" (http://www.cleanmpg.com/forums/showthread.php?t=14151)


Looks like an excellent article, and would be well worth your time.

You can ignore what I said earlier and just follow this if it's an AC issue.

And yes, it's been getting very hot (and very humid) in our area (50 miles east of KC here).

Don't think wheel alignment will be an issue on a new 09.

I am getting 55 MPG (70 MPG Imperial) on my 09 HCH. I only have 1400kms on it, however on the west coast we are only about 70 degrees right now. I put my tires up to 40 psi.

What about tire pressure? It seems to make a big difference in mileage in my HCHII. I usually make sure I have at least 37-39PSI per tire.

I had a nail in my back tire and the pressure was down to 25PSI, and my mileage was lower for a few weeks

I just checked it, I have 44-45 PSI in all tires. So, that's not it.

Jon

Hi Jon;

- Take the tire pressures up a bit more

I am NOT going to go above the max pressure printed on the sidewall. Actually, a couple tires are 1 PSI over the 44 limit, I figure I can get away with that.

- Have a look here just in case: "HCH-2 AC tips" (http://www.cleanmpg.com/forums/showthread.php?t=14151)

I've already read it several times, thanks. But, I don't think I can do much better than I already am.

- Wheel alignment!!!!

Very interesting thought, I'll see what I can get them to agree to as it is about due for the first oil change. I did run over some road debris, I think it was half of a truck leaf spring, last week. I t made a big clunk underneath. Could have affected alignment. Unlike the dealer of my first HCH-II, this one seems to be one of those high-volume in-and-out sorts of places that might not agree to any work not totally necessary. I fear I'd have to pay full price for a 4-wheel alignment, with typical dealer markup in might be over $200.

What speeds to you usually drive at?

My commute to work is a mix of 30-35 MPH sub-urban streets and a bit of 55 MPH highway. I generally keep it between 50 - 55 MPH there, and DWL. So, I was expecting a LOT better mileage than this. There's a long light getting out of work, so I usually FAS there.

Jon

Hi Jon;

I did not know your actual tire pressures, but the ones you're sporting should give you plenty of MPG headroom. The MPG you are getting does not show it at all.

Your speeds are excellent as well.

How about your glides? Are they short lived compared to your 2008? Does the car track straight? How are you tires wearing?

Cheers;

MSantos

Hi Jon;

I did not know your actual tire pressures, but the ones you're sporting should give you plenty of MPG headroom. The MPG you are getting does not show it at all.

Your speeds are excellent as well.

How about your glides? Are they short lived compared to your 2008? Does the car track straight? How are you tires wearing?

MSantos
I can't glide very far most of the time, there are little hills EVERYWHERE. But, I can't DETECT any difference in glide length in the 2009. There is a nice, gently hilly road with an overall down-grade that I can do really good mileage on coming home. On some of the small up-grades I can get over them with just a little assist motor and no ICE, and otherwise just short blips with the ICE.
Also, there's a nice flat section of the highway where I can set up an economical cruise at about 60 MPG. But, all of this is in short sections, with bigger hills, traffic, and other mileage killers all along the drive. But, I was OK with the slightly better than 50 MPG I was getting a few weeks ago, and I've been using the AC since mid-May, I think. St. Louis definitely gets hotter before Canada.

The car tracks as straight as I can tell, so there is no obvious misalignment detectable at the steering wheel. I will try to examine the tire tread, but I've never been real good at detecting the "feathered edges" that the experts can spot from 20 feet away.

When I was getting 56 MPG with the 2008 HCH-II, I was using a different route, as our local highway was closed for total reconstruction. I will have to run that route to see what mileage I can get now. A few MPG won't get me to drive city streets with lots of stop lights, but 10 MPG might make me go back to the streets.

Jon

Can you check the engine oil level? An overfill will kill your FE.

I agree. Trying your old itinerary again may be the best yardstick.

Can you check the engine oil level? An overfill will kill your FE.

I agree. Trying your old itinerary again may be the best yardstick.

The oil has never been changed, or filled. It certainly shouldn't be going UP! Well, that WOULD explain where the gas is going, of course. I am about due for the first oil change.

But, I was getting ~52 MPG several weeks ago on this daily commute. The only thing I can think of that has changed is temperature, and a different tank of gas.

Jon

The temp is adjusted by adding heat to that cooled air. It's much more efficient to manually cycle the AC instead of letting the lazy computer do it.

Exactly. That's a horrible way to regulate the air temperature, by chilling it to the max with AC and then mixing in heated air if you don't want it fully cold!

I'm pretty sure the newer hondas, like this one, cycle the compressor on and off as needed. Much more efficient this way.

Hi Jon;


- Wheel alignment!!!!

On the subject of wheel alignments: I always have the dealer perform a wheel alignment at the time of purchase on any vehicle shipped from Japan.
MSantos

Well, just to expand on previous comments, when I picked up this vehicle, it had 4 flat tires, and the TPMS was going off every minute I drove! They took it out for a "test drive" before turning it over to me, so I assume it was doing that for them too. All 4 tires were at or below 25 PSI, I think one was at 18! I took it straight home and pumped them up properly.

So, I have the GREATEST doubts this dealer will be willing to do a complementary 4-wheel alignment. With my last HCH-II and a different dealer, they refused to do an oil change until the wrench light came on - I never got to drive that one long enough for that.

I am coming up for an oil change, and I got a notice for what sounds like a software update related to extreme cold operation, so I will mention this poor mileage to the dealer, but I suspect they will blow me off as a nut. "Hell, you're getting better than EPA mileage, what the HELL are you complaining about?"

Jon

Hi Jon;

I think you are right. Unfortunately some (if not most) dealers will do just that. Brush you off. Anyway, make sure you at least get the right oil and the right amount poured in because the wrong oil will knock 10-15 MPG right off the top. ;)

With regards to the wheel alignment... that is a tough one. It looks as if your only option is to find a shop that will give you a quick and inexpensive verdict on the alignment!?
Alternatively, you can always wait a bit until it is time to do one. Most "in the know" recommend an alignment on a regular basis perhaps every 2 years or even sooner depending on the road quality and mileage. In my view this is a good policy since an alignment is still cheaper than a full set of properly balanced tires not to mention the erosion in fuel economy.

Cheers

My honda dealer just sent a flyer for a $59.95 all-wheel alignment. Not sure if this is a good price, but it doesn't sound too bad

We have also took a bad hit concerning summer temps and A/C on the 09 HCHII.

Back when the temps were in the 80 to lower 90's and we used the A/C on the hwy set 78 to 82 I could get 56 to 58 mpg out of the car running 55 to 60 mpg and using basic tactics. Now that temps have went up to 98 to 102 I have not been able to get much above 52 mpg out of it on our daily grind in the afternoons. The morning commutes in 78 to 82 temps It's a no brainer to get into the lower to mid 60 mpg area.

The A/C seems to be really dragging the already under whelming power way down. Battery management is easy for me. I think it troubles the wife a bit. So I'm able to keep 5 to 8 bars easy concerning the battery.

I think its high intake air temp causing the problem myself. I've noticed the MZ3 getting a tad sluggish of late when I drive it. Then it dawned on me I had not put it's OEM cool air intake back on. While it does not have the WAI tube on, it's still drawing hot air in the air box from under the hood. HCHII does this by default! Even if we sweat it out and go with no A/C, windows cracked and the dash blowing outside air the car is still sluggish. It also becomes harder to SAMBA and SAHM. It will still glide and such. I don't fas it and even glides seem kind of worthless if you can make it SAMBA or SAHM. I don't think it will glide or fas as good as the awful Ranger. I need to do a coast down test with it.

In short,,, I think its high intake air temps in combo with A/C.... I'm seeing it also....

We have also took a bad hit concerning summer temps and A/C on the 09 HCHII.

Back when the temps were in the 80 to lower 90's and we used the A/C on the hwy set 78 to 82 I could get 56 to 58 mpg out of the car running 55 to 60 mpg and using basic tactics. Now that temps have went up to 98 to 102 I have not been able to get much above 52 mpg out of it on our daily grind in the afternoons. The morning commutes in 78 to 82 temps It's a no brainer to get into the lower to mid 60 mpg area.

<snip>

In short,,, I think its high intake air temps in combo with A/C.... I'm seeing it also....
Well, I probably wouldn't be complaining about 52 MPG at near 100 F. We've had a combination of upper 80s to upper 90s and I'm getting anywhere from 42 to 47 MPG, and can't get above that, in mixed city/hwy driving. A couple months ago, when I reset the trip odometer after a gas fillup, I could maintain 75 MPG for a day or so until I got stuck in traffic or whatever. Maybe it is all temperature, then.

I took two highway trips, and ran rather fast 65 - 70 MPH, and was getting 47 MPG and thought that was mediocre, but I had a ton of stuff in the car, and used cruise control, too. Now, I'm driving myself to work in an empty car, and getting 47 MPG on city streets and such, with careful high mileage efforts.

Jon

Hello,

I'm a newbie and have been watching this thread with great interest. I have an 09 HCHII and live in the DFW area. I bought the vehicle in January of this year and use the vehicle primarily for commuting ... 30 miles to and from work ... with mix of city and highway driving.

This week I have been only able to achieve 52.38 mpg on this weeks "tank" of gas due to the heat. I have tried to adopt the using AC w/minimal FE loss (keep it set at 84-86 or in auto mode) along w/other basic techniques discussed in this forum.

In more modest weather I am able to usually get 54-57 mpg on the weekly tank of gas.

Being a newbie ... the hardest thing to adjust to with this heat ... is the almost daily "afternoon" battery drain and associated recal. On the trip home I'm initially faced w/stop and go and a long gradual grade. By the time the car "warms up" ... damage has been done to SOC and we're in recal mode.

I guess this is my long winded way of saying I am also seeing similar results to what others have shared in this thread.

No recals here that I know of.

Are you sure it is a recal and not just a forced regen back to full?

... the hardest thing to adjust to with this heat ... is the almost daily "afternoon" battery drain and associated recal. On the trip home I'm initially faced w/stop and go and a long gradual grade. By the time the car "warms up" ... damage has been done to SOC and we're in recal mode.


Hi kgenaidy

Welcome to CleanMPG !!

Yes, your experience is very familiar to us. For instance, just last evening we went out to eat with my wife's 07 and because it was pretty hot, the AC was on and conservatively set. Family was happy and car was doing good mileage wise.

Everything was going fine until we encountered road construction and the traffic entered a stop and crawl. At that point when I looked ahead and saw the big lineup I knew an SoC crash was inevitable unless the traffic picked up some speed.
Well, no more than 10 minutes later the SoC did crash to 1 bar and the ICE came on and stayed on until we arrived to our destination. Mileage? In the dumps.

Such is life in the warmer weather with AC on and in Stop-n-crawl.

Cheers;

MSantos

I'm not positive I am getting the term correct for what is going on ... but MSantos' description nails the behavior perfectly on the Soc and the re-charging.

First couple of times this happened ... I thought something was "wrong" w/my vehicle. After reading articles on CleanMpg ... it helped me realize this is an expected and normal behavior.

This board really helps a newbie like me understand and gain valuable insight into our vehicles.

Thanks to all for the participation and information shared!

I just spoke with the wife. She is very frustrated with the HCHII. She is on a trip from Okmulgee, Ok. to Stillwater, Ok. The car is showing 44.6 mpg on a fresh tank. She is driving the two lane hwy's keeping her speed between 55 and 60 mph. She does have the A/C on in auto mode set to 82f.

She is not happy at all right now. Very pissed would be a understatement. She's said if this HCHII turns out to be a POS like the 06 Civic there will be no more Honda's at our house.

Is she frustrated with the mileage or the handling?

Is she frustrated with the mileage or the handling?

The mpg. The two lane roads shes on are not demanding at all. Some hills and over all straight. She is peddling the car and not using the CC. I checked the tires this am before I left for work in my always fun to drive MZ3. Heck I got 44 mpg out of the MZ3 this morning with a few high rpm stabs, A/C on some of the time running the psl. ( I was running late ) I did throw some fas'ing action in also.

Okay. I can definitely understand her frustration but in the grand scheme of things, would she be even approaching that with her old car in these temps? Over all, I think her average fuel economy will more than justify the purchase and other than acceleration and "squishy" handling, it sounds like a very comfortable vehicle for her.

Okay. I can definitely understand her frustration but in the grand scheme of things, would she be even approaching that with her old car in these temps? Over all, I think her average fuel economy will more than justify the purchase and other than acceleration and "squishy" handling, it sounds like a very comfortable vehicle for her.

She would only be getting 35 mpg in her Accord. But the fact remains. The HCHII has shown It will not get EPA at 65 and 70 mph with auto A/C use with CC. She is also finding out she has to work it to get EPA hwy at lower speeds with A/C. I have to work it to get 52 mpg this time of year hwy with auto A/C. While this good. It's still underwhelming considering the work needed.

She could drive her Accord with out worry just keeping the speeds down and get or beat EPA city or hwy.

---------

She just called and reported back 45 mpg for the drive. She is at her destination and very frustrated with the mpg. She was expecting atleast high 40 mpg segment if not 50 mpg even.

This is not close to what we expected. It's now looking like it might be hard to hold on to the expected lmpg of 50 mpg. I haven't posted the last tank yet. But at 51 mpg who's in a hurry. The heat is really hurting this car bad. Even with the A/C it's taken a nose dive. I will start looking into the intake air temps with my SG and see if a cool air intake mod is needed. Sure feels like it needs on something awful. It has got way gutless since the temps have went to the 100f mark. As of yet we have not seen a hard forced charge or a recal in the car. I left it for her after me driving it home yesterday with a full pack. First time I talked with her the pack was at 7 bars. Last time it was 6 bars. she said it never dropped below 5 bars for the trip that she saw.

I know she is trying. This has her pissed!

The HCHII has shown It will not get EPA at 65 and 70 mph with auto A/C use with CC.

Hi Jeff;

At 65-70 MPH? No way. Not likely you'll get EPA with the AC on, unless you set the AC to run on electric only and even then you're pushing it.

It took me a good year or so to get my wife to nail the proper procedure on her HCH-II, but now she still gets good mileage without much of a miss when the temps are above 30C (86F). Stop and Craws are the worst, but steady highway speeds should not be.

Still, your results appear consistent with the feedback from folks who drive the HCH-II at those speeds with the AC on, and that alone tells me it is "normal".

Obviously if it still does not meet you expectations then perhaps that is enough to overshadow any of the other benefits the car has to offer.
At least in that department, it appears our wives would have very different opinions and impressions the cars.


Cheers;

Psyshack - also remember that MPG stated on the trip average display is usually understated on the HCHII. This means you could be getting better mileage than you think.

So if your wife sees 44.6MPG, it could be 46 or 47MPG in reality. The only way to know is to divide mileage by a known tank (full would be best).

On mine, if I get 50MPG average on the display, its almost always 52 or more based on real measurement.

Hi Jeff;

At 65-70 MPH? No way. Not likely you'll get EPA with the AC on, unless you set the AC to run on electric only and even then you're pushing it.

It took me a good year or so to get my wife to nail the proper procedure on her HCH-II, but now she still gets good mileage without much of a miss when the temps are above 30C (86F). Stop and Craws are the worst, but steady highway speeds should not be.

Still, your results appear consistent with the feedback from folks who drive the HCH-II at those speeds with the AC on, and that alone tells me it is "normal".

Obviously if it still does not meet you expectations then perhaps that is enough to overshadow any of the other benefits the car has to offer.
At least in that department, it appears our wives would have very different opinions and impressions the cars.


Cheers;

Hi

I realize that high mph will degrade mpg. I just would have thought the new EPA numbers reflected higher speeds and AC / acc. use. But when the wife struggles to get EPA hwy with the car well below psl with A/C set in auto mode at 82f. That isn't right. And I struggle with it to get 52 mpg the last week or better since 98f to 102f temps have set in. It makes one wonder what is going on here. I honestly think it's the intake air temps being high. The A/C is more than likely a 4 mpg hit right off the bat.

I will try to infestigate the IAT when the wife gets home tomorrow with the SG1.

A side note: I did get EPA hwy when I took the MZ3 out at lunch to run over to my daughters. Drove it slow, A/C full blast all city driving with no hypermiling except running under posted speed limits.

Psyshack - also remember that MPG stated on the trip average display is usually understated on the HCHII. This means you could be getting better mileage than you think.

So if your wife sees 44.6MPG, it could be 46 or 47MPG in reality. The only way to know is to divide mileage by a known tank (full would be best).

On mine, if I get 50MPG average on the display, its almost always 52 or more based on real measurement.

The wifes car has been dead on at 52 mpg mark and under. Once it reports more than 52 mpg it then is off in mpg's favor. And I have seen it at 2 mpg or better. My MZ3 is always 1.5 to 2.0 mpg off in my favor,,,, like clock work. :)

Hi Jeff;

At 65-70 MPH? No way. Not likely you'll get EPA with the AC on, unless you set the AC to run on electric only and even then you're pushing it.
Cheers;
How do you get the AC to run on electric power only? I'm not sure that would be an energy saver except in the case of a lot of down hills so you have regen to burn.
But, I'd just like to know.

I think I do get about EPA highway rating on the '09 HCH-II, but not much better. I am used to getting WAY better than EPA with most other cars, either city or hwy.

Jon

How do you get the AC to run on electric power only?

The AC will run on electric only if the temperature differential between the ambient and the temperature setting of the climate control is low. To rephrase it, the electric half of the compressor will be used "exclusively" to perform small temperature corrections or simply maintain the existing temperature. The only thing we need to do is create the conditions for that to happen.
The other time the electric compressor works is when it is being aided by the belt assisted half (to correct the biggest temp differentials).

AC use is never a free deal as there's always loss to contend with. The question then becomes: How big is that loss and can we minimize it?

Assuming that you will have at least a few unavoidable opportunities to regen and that you are able to manage your electric assists, then it is also possible to make use of what you put in the pack for AC use. The alternative to this is for the vehicle to fire up the ICE and keep it running at an idle consumption rate that is not very nice - especially when you are stopped.

It is too bad we do not have an easy way of seeing when electric only AC is in use, but you can still tell it is working based on the absence of the usual/expected engine load and the difficulty to bump your SoC up.
In the most extreme of cases (I really hate these), you'll actually see your SoC take a steep dive depending on whether we're able to keep the SoC in check or not.

Cheers;

MSantos

Hi

I realize that high mph will degrade mpg. I just would have thought the new EPA numbers reflected higher speeds and AC / acc. use. But when the wife struggles to get EPA hwy with the car well below psl with A/C set in auto mode at 82f. That isn't right. And I struggle with it to get 52 mpg the last week or better since 98f to 102f temps have set in. It makes one wonder what is going on here. I honestly think it's the intake air temps being high. The A/C is more than likely a 4 mpg hit right off the bat.

I will try to infestigate the IAT when the wife gets home tomorrow with the SG1.

A side note: I did get EPA hwy when I took the MZ3 out at lunch to run over to my daughters. Drove it slow, A/C full blast all city driving with no hypermiling except running under posted speed limits.

My guess would be the EPA tests do not include temperatures as extreme as you are experiencing. Ac use is very mileage costly regardless of whether the compressor is engine driven or electric driven. Even with otherwise lost regen you still had to gain the inertia with battery or engine.

Idle speed losses (non hybrid) double with AC use. The cost is probably in the range of .2 to .3 gph for AC use alone. That is going to nail your mileage regardless of the original power source.

regards
gary

Lets remove the A/C and my observations of higher speed. Just remove it. I should have never brought it up. My bad!

Remove those two factors and I'm still seeing lower mpg and a laboring engine with a full pack at higher temps. My gut is telling me it's the higher intake air temps.

Take our daily grind drive into Tulsa. If there is no wind the trip home is almost always better than the drive in. Of late with the higher temps the drive home has been a real chore.

Last week when the higher temps set in on us I had a real good run into work. 81f no wind with my normal 55 to 60 mph speeds. Windows down radio blaring away. That was good for 67 mpg. Not elite but very strong. We decided when we got to my office to really try for a good day no matter what the temps as long as the winds did not kick up. The winds did not come up. The wife did great on her leg of the day. Mixed city/hwy came in at 52 mpg. I was just amazed she pulled that off. My turn came to get us home. No wind and it was hotter than heck. We loaded up on water put the windows down. Both of us expected a record day. Didn't happen. All I could get out of the car was 57 mpg for the trip home. The pack was in good shape. We decided there would be no more of that foolishness. The heat really took it out of us by the time we got into the house. We both expected to see a 70 mpg run for the drive home.

What I noticed was a much more sluggish drive in the heat. It's like cold corn syrup at best. :) It was harder to get into SAHM in areas of the drive that should be a no brainer. SAMBA was even harder to get and glides became very abrupt and control became overly sensitive. Fake shift was gone.

One thing that has surprised me is its city / small town mpg. The wife has been very clear she will not drive for mpg at all on her weekends. She just want's to get in her car and go. And she does just that. I've seen her park it with Okmulgee segments in the high 20's to low 30's. I on the other hand have no problems with segments in the 70 to 80 mpg range around our small little town. And have had several that went 101 mpg to my best at 106 mpg. The day I got the 106 mpg segment she was in the car with me and uttered " your sick " :)

Just have to figure out this low mpg issue when the heat pours on.

Just have to figure out this low mpg issue when the heat pours on.

Could it be the battery efficiency is being inhibited by the high heat causing a constant charging action (beyond the AC use)?

I'll be very interested to see your colder air intake effects in those conditions.

Taliesin, in heat the battery tends to want to discharge as that will cool the chemistry. Charging causes it to warm up. You can see it in relative propensity for assist and regen in different temperatures. Below zero, my Insight will throw regen very easily. In hot weather, it wants to assist like crazy when accelerating.

I'll be very interested to see your colder air intake effects in those conditions.

Taliesin, in heat the battery tends to want to discharge as that will cool the chemistry. Charging causes it to warm up. You can see it in relative propensity for assist and regen in different temperatures. Below zero, my Insight will throw regen very easily. In hot weather, it wants to assist like crazy when accelerating.

I wasn't sure, but it was a thought. Could it be that it's becoming so assist happy that it's causing a charge/assist cycle?

Just kinda brainstorming right now. I know that this heat we are experiencing down here right now isn't something you are used to.

I personally am used to the heat (grew up in SC), but the Insight mostly isn't. It did go through some 100+F days last summer and worked just fine -- though assist happy.

It is good thinking, but any charge/assist cycling should show up on the display. I'm seeing similar sluggishness in my Insight but in that case I know it is charging because 1) my Calpod disabling switch gets me back to normal operation -- something I unfortunately didn't notice until right at the end of my trip home yesterday and 2) the car never reaches 20 bars no matter how much regen I use. I'm going to do a 12V pull to force a full recalibration event -- the computer seems to be confused.

Speaking of which, Jeff -- does the car still perform better in the mornings when it is cooler? Mine does not so it makes sense to go after the computer -- how about you?

Could it be the battery efficiency is being inhibited by the high heat causing a constant charging action (beyond the AC use)?

I don't think so unless the car has a stealth agenda concerning regen. I work very hard to stay out of the pack for the most part except when it comes to pulling hills and some lights when traffic is stacked up and folks are fuming behind me. <<< That is when fake shift can be your friend IMO. And honestly,,, i don't glide the car like I thought I would. I get some free regen then look twords SAMBA. Even with assit extending glides the car is no where near as good as the Accord in a full blown fas, Civic or MZ3. It's glides even using assit are about on par with the Ranger in a fas. Really pretty sad IMHO. And a fas in my book is worthless in the car.

I have been wanting to do some coast down testing in the HCHII and tie it to this data.
http://www.cleanmpg.com/forums/fuel-economy/t-ideas-on-pushing-the-civics-mpg-farther-4713.html
And this. http://www.cleanmpg.com/forums/showthread.php?t=6215&highlight=coast+testing

I will do the test in full fas mode and glide / assist.

It is to my surprise taking me longer to figure out this car than I would have ever thought. And honestly there have been some emotional and mental road blocks along the way. As of late I've went from flipping the CVT input device off and wanting to put my fist through the Navi screen or just flat out pulling over and walking. To yelling the Serenity Prayer when my frustration level with the car peaks. :)

I personally am used to the heat (grew up in SC), but the Insight mostly isn't. It did go through some 100+F days last summer and worked just fine -- though assist happy.

It is good thinking, but any charge/assist cycling should show up on the display. I'm seeing similar sluggishness in my Insight but in that case I know it is charging because 1) my Calpod disabling switch gets me back to normal operation -- something I unfortunately didn't notice until right at the end of my trip home yesterday and 2) the car never reaches 20 bars no matter how much regen I use. I'm going to do a 12V pull to force a full recalibration event -- the computer seems to be confused.

Speaking of which, Jeff -- does the car still perform better in the mornings when it is cooler? Mine does not so it makes sense to go after the computer -- how about you?

Car is great in the cooler mornings. Normal as a matter of fact. Assist regen ratio hasn't seemed to change a bit. And honestly I have not heard the fan run a lot cooling the electronics. It has it's own little sound. The wife can even hear it. It's most notable after a hard glide regen or a hard assist. Then its gone. Which is really rare when I'm at the wheel. I like to see that pack full and stay up there. So I tend to drive for the pack and all that it brings. Also I have yet to see a recal or a hard forced regen in the car. I've explained the behavior and reality's of such actions taken by the car to the wife and she reports not seeing one either. Maybe today will be the day as she will be driving back from Stillwater in the heat of the day. They are forecasting record heat today, between 102 and 105 depending on were your at. There is a slight breeze out of the south today. But the wind should not affect the wife much today as she will be traveling in a eastern direction with the lay of the land diffusing some of that for her.

When she gets home I will get in the car with it hot and take it out for a spin and look at the IAT. Then check them tonight after it's cooled down a bit.

My car is behaving the same as psyshack's. It operates normally in the morning, but the drive home after a 100F+ heat soak is difficult. Almost every day I get a forced charge, even when my SoC is 5+, it seems to take forever with a 2-3 bar forced charge for the SoC to increase, and then the SoC suddenly increases to 8 bars which, until the last few weeks, I had only seen once before - usually 7 is max. Sometimes the SoC will drop to 1-2 bars (as in a recal) shortly after the forced charge begins, but normally not. Very frustrating, because to me it doesn't appear that my battery needs a charge, but it's force charging anyway. Also, it seems reluctant to accept regen, i.e. in a situation where I might normally see full regen under braking, I only see 2-3 bars.

This behavior is different from last summer's when I would get about a weekly recal, i.e. SoC drop to 1 bar, forced charge brings SoC back up to 7 bars within a few miles. A/C use would almost guarantee a recal.

I can't explain why the car is behaving differently between last summer and this, except that the dealership may have squirted a software mod when I had the oil changed last month. It does seem though that this car doesn't really like the heat (or cold, for that matter).

Having said all that, I am currently on one of my best tanks - 64.8mpg indicated, 575 mi on this tank so far with 4 pips remaining. It acts a little funny in the heat, but it's still better than the cold.

Based on the original post and the experts on HCHII input I feel you are getting about the right mileage you should be getting using E10. Based on testing by members on this board most have seen a drop between 8 and 12 percent using E10 over regular straight gas.
Lets say using the E10 you see a drop of 10% your cars EPA rating to 40.5 mpg.

The EPA tests their cars at 60-70 degree air temperatures and use pure gasoline.

It's easy to beat EPA numbers at 60 mph if your running "straight gas" and the temperature is under 70degrees.

I know it is frustrating not to see 50 plus mpg on a regular basis but you have two variables beyond your control working against you. If your seeing high forties at the pump using E10 then your doing well. Don't trust the on board factory display. Others have already warned you on their inherent inaccuracy.

My 960 Volvo gets 29.25-29.75 mpg highway at 65 mph on straight gas. I'm lucky to see 27 mpg on E10 on the same route and speed.

Based on the original post and the experts on HCHII input I feel you are getting about the right mileage you should be getting using E10. Based on testing by members on this board most have seen a drop between 8 and 12 percent using E10 over regular straight gas.
Lets say using the E10 you see a drop of 10% your cars EPA rating to 40.5 mpg.

The EPA tests their cars at 60-70 degree air temperatures and use pure gasoline.

I know it is frustrating not to see 50 plus mpg on a regular basis but you have two variables beyond your control working against you. If your seeing high forties at the pump using E10 then your doing well. Don't trust the on board factory display. Others have already warned you on their inherent inaccuracy.


I got up to about 56 MPG on the last full tank with my 2008 HCH-II that got wrecked. That wasn't as hot weather as we're having now, and I'm sure that has an effect. That was using E10, the only stuff we can get here. I've never gotten better than 52 MPG on the first part of a tank with the 2009 HCH-II, and am now getting 46-47 MPG per full tank. The trip fuel consumption display has been quite accurate on both of these cars, certainly always within 1 MPG of the calculation from the pump.

The problem with St. Louis is it has a short fall and a REALLY short spring. Some years, spring is just one day between winter and summer! This year it was a bit more gradual.

Jon

Hello all

I did get a chance Sunday to do some testing. The heat wave was broken Sunday. We got a weak cold front come through thank goodness. The wife did not get home until late Saturday night. So no testing was done at that time.Here is how the test went off. I drove from our home in Okmulgee south to Henryetta and back. The round trip is 25.9 miles. I ave. both going and coming. First trip was on a cold engine with no A/C, second trip was a hot engine with A/C. Ambient air temp was 87f. A/C set to Auto 82f, recirc on.

No A/C: 63.7 mpg, IAT 55-60 mph 94f, 30-45 mph 102f, Ave. speed 44 mph. SoC 6-7 bars.

With A/C: 58.9 mpg, IAT 55-60 mph 98f, 30-45 mph 105f, Ave. speed 44 mph. SoC 7-8 bars.

These numbers will be my baseline and referenced when we get some very hot summer temps in the future. The A/C hit was 4.8 mpg on this test. Safe to say a 5 mpg hit. This I find to be just a tad high. The hit in the Ranger, Accord, R-18 Civic and MZ3 are right at 4.0 mpg

Also of note the No A/C test was run with the two front windows all the way down. The With A/C test was run with the windows up and the car completely buttoned up. If you put a lot of stock in aero, then the mpg number with no A/C could of been higher if I had ran with the windows up. Windows up for all the testing might have shown a larger delta between the two.

Temps might climb up to the higher 90's today. Will just have to see. But no 100 plus temps expected for at least a week or better. I also came down with a stomach bug Sunday night and its still running it's course. It hit the wife last night. So we are both feeling poorly right now and off work.

We will be waiting on higher temps here and to get feeling better.

Hi Jeff;

You were obviously running the AC very conservatively and with a steady foot, otherwise I suspect the MPG hit would have been a bit higher than 5 MPG.

That is the thing with these cars (including the Prius). After all is said and done , it remains a game of minimums where even the slightest deviation in variables will cause dramatic differences in the MPG results. Its like an acrobatic act on the high rope. The higher the rope, the more significant the tiniest breeze will become.

Also on this note, the higher the baseline MPG the greater the amplitude of the perceived loss (a 5% loss in a 50MPG car is not the same as a 5% loss in a 25 MPG car).

Anyway, for as bad as summer can be, you have to wait for winter to show how truly dramatic the FE swings can be in this car. :eek:


Cheers;

MSantos

Just a followup - We have had most of a week of cooler weather and the mileage has been creeping up. I am up to about 48.3 MPG so far. So, the past week's heat was definitely a major factor in the crummy economy I was getting earlier. Still, I'd like to get over 50, but it seems pretty hard to do.

Jon

Another followup - how long does it take the engine computer to remap the mixture tables after you change fuel grade? I live in an EPA enforcement area (St. Louis, MO) so I can only get E10 or other oxygenated fuel here. I took a couple of road trips in the past months and probably got pure gasoline while there. Then, arriving back in St. Louis, I had really LOUSY gas mileage. It looks like a dip of 5 MPG, from a normal of a little better than 51 MPG down to 46 or so.

The ONLY thing that has changed is time - driving habits, speeds, temperatures, etc. have not changed much at all, but mileage has suddenly started creeping back up in the last week. So, it seems like maybe it takes ~750 miles for the computer to readjust the mixture after going from pure gas to E10.

The only other car I ever had that showed something like this was a 1986 MR2, my first fuel injected car. (An awful mileage pig, by the way, due to insane "performance" gearing.) I actually took it back to the dealer after a fuel change due to rotten idling, engine shutdown at idle, etc. They correctly diagnosed it as change in fuel type, it took most of a tank to recalibrate, then ran fine.

So, has anyone else seen this, a temporary poor mileage condition that corrects itself after about a tank and a half when changing back to E10?

Thanks,

Jon

Jon

Our HCHII has only had one tank of booze gas in it. And that was the dealer tank purchased at QT. Only real gas since. The second tank was about 3 mpg better than the first. That is easy to write off to the car breaking in and us getting use to it.

But,,, I have had booze gas in the 05 Accord, 06 Civic and the 07 MZ3. All three of those cars showed a 3 to 4 mpg hit as soon as you started driving. The 06 Civic loved premium in the winter. But floundered on it in the summer.

Most modern cars adjust very fast to fuel changes. As for the Yota you had. I bet there was some water or other trash in the gas that caused the issue's.

Jon

Most modern cars adjust very fast to fuel changes. As for the Yota you had. I bet there was some water or other trash in the gas that caused the issue's.

Well, I came back from a road trip where I am pretty sure I got pure gasoline. I had AWFUL mileage on the first tank after I got home, around 46 MPG for the whole tank. Next fill-up I started out getting about the same poor mileage, and then when about half the tank was used up the mileage started to improve, going from 46 now up to 51 MPG and still rising. This is with E10 here at home. I can't detect any change in other conditions that might have caused it (driving style, tire pressure, temperature, route, etc.)

As for the '86 Toyota, it did it enough times that I'm pretty sure it wasn't water, just that the computer didn't adapt well to fuel type change.

Jon

Hi Gang - I'm new to this forum also. Good thread. I just purchased a used 2006 civic hybrid and have been averaging 36.5 MPG or so. Mostly city driving, I live in Houston, so AC is always on. Although I am interested in maximizing mpg, I am also interested in being comfortable, so the AC is set to 76. It's HOT in Houston.

Tires are filled to 40psi. The charge/assist seems to be working correctly, and I am getting comfortable with the process.

Any idea if my 36.5 is unreasonably low? Anything I should do? I just changed the oil to mobil 1 0w20. I think the last oil change was a little over-filled.

According to the dealer, the car has received all the appropriate updates.

Any thoughts?

Thanks!

Welcome, EMatzen!

In case you haven't yet read the "sticky" by Msantos about optimal use of your A/C, start there. Another valuable guide is Tarabell's report linked to the home page.

There are a great many factors which affect your mpg. Hot weather adds its own set of additional challenges.

Extracting the most out of your HCH-II involves learning how to "glide" where you apply just enough pressure to the gas pedal to eliminate regen but not so much as you 'refire' the gas engine. The fuel consumption display (iFCD) will give you a clue and also the slight lurch you will feel when this happens.

I would think that you will get to 40+ mpg fairly easily and approach 50 mpg when it cools off to the 70's.

Good luck. You will learn a lot about your car from those who share their knowledge and experience on this site.

Did you just recently start using the AC?Also my 1st thought.

Warm weather more than makes up for the E10 (or more likely, I use E10 year round)

With my new SG in hand I can start testing again.

My gut is telling me HCHII really does not like high or low ambient intake air temps. This morning as the wife and I left for work with the new SG setup at Waynes defaults. It was 66f. WTF is up with that for Ok. in August, WOW!!!!!! Within 1/2 mile the water temp was up to 178f and I had Auto stop at my first stop sign om less than a half mile. With in 3 miles the cooling system was cycling at 205f. And intake air temp was at 89f. After 5 miles it was 30f above ambient temp.

I wonder if HCHII and think about it a lot concerning intake temps. Would it work better with a CAI in the summer months and a WAI mod in the winter? From what I;ve seen it does not like to be baked like a real Insight mill, R-18 powered Civic or a K24 Accord......

Mine does best in 70 to 80sF anythig in the 60s or below is bad MPG the 90s and above are decent but I start thinking about AC and the numbers are already down so whats a little electric AC...