I just purchased a HCH 08 from a used car dealer with 156k on the clock. My battery stays at 4 bars, but I DO feel like it takes a while to charge it higher than 4. Sometimes it will charge up three more bars, but majority of the time it does not. I have spent all night reading about techniques and how to coast in full electric and so on and so forth on clean mpg.com. I have a read A TON around 50 on this forum of peoples Q's & A's. Yes, yes ill make sure my oil is 0w next time. All my tires are at 44, maybe 45. Very close to those numbers. I am getting better at reject regen, and coasting on full battery. I now pay very close attention to the IFCD? On the left. But, I have some questions STILL.

1. Why is that my assist comes on so HARD when I am barely touching the pedal. around 1700rpms? I feel as if it WONT come on ONLY if I am giving it like 3% throttle? What? Is there a problem? I treat this like a game I want to get better at, but I feel as IF my numbers are borderline average and that worries me. No IMA light as come on, but I have seen my battery drop to 2 bars once after leaving a parking lot earlier today.

2. I have to basically FIGHT to get a steady 39.7 MPG reading on my dash. I know, I know, there's a 5% difference. The other night, I got 43 calculated mileage at the tank which BTW, coming from 25mpg is good in my book. But ignorance is bliss. With everyone else on here having readings closer to 50 I feel as if im in a gas guzzler. I live a few hours East of San Francisco so climate is not a factor. My mpg is below average, what does this mean? I've only had the car for two days but I've put at least 300 miles on it. Why does the battery sit at half life for the majority of the time and why do I have to fight so hard to get below average mpgs?

 

So I reset the mileage and took a quick errand. I forgot that I had messed up a few times throwing it in neutral and forgetting it was in neutral and revved a little which tainted my average current tank mpg. Anyways, this was 50/50 city highway driving favoring downhill stretches.




I also reset it on the way home just to see what I could get. I took 70% city streets. Also, I reversed out of the parkinglot to get onto the street so my mpg starting was at 15mpg for the first 3 minutes. Not sure if that matters, but here are my numbers.



I guess I'll do more reading and see.

 

2 bars. There it is. You should never see two bars unless you are in a negative recalibration. A single recalibration doesn't mean anything, but they typically signal the initial deterioration of the battery pack.

Watch your SoC gauge like a hawk. Every time you see it drop to two bars at the rate of 1 bar per second, you are in a recalibration or forced regeneration. An occasional recal isn't a big deal, but frequent ones can be mileage killers.

Frequently, a positive recalibration follows a negative, i.e., the gauge goes to full at 1 bar per second after a forced regent. If it's NOT doing this, that's a good sign. negative + positive recals = deteriorating pack.

Wife's birthday tonight... more later.

Steve

 

First off, I just wanted to say thank you for replying to my post. I do watch it like a hawk. I want to become a hypermiler too. I believe this was the first time I saw a negative recal occur. I did watch it charge because I was sitting still at a light while it was charging which lead me to post for help. But, right on ill keep watching it to see what happens again.

 

A few comments:

• Hypermiling in a hybrid is different.
• Coasting instead of regen can worsen mpg - better to do a controlled throttle coast, i.e., back off until you see 1 bar of regen. Never reject regen until you have mastered the nuances of this car.
• LRR tires (EP422) will buy you about 3mpg over highly inflated non-LRR tires.
• Don't overinflate past sidewall.
• Ensure underbody panels are intact.
• Replace CVT fluid every other oil change (12-15K miles).
• 300 miles is not enough to make meaningful assessment.
• Elevation changes DESTROY mpg.
• Accelerate at constant 1600-2000 rpm for normal driving. Try to maximize assist in this range. It will vary based on SoC.
• 156K mi cars don't perform as well as newer cars.
• IMHO, if you're dealing with hills, anything above 40mpg in mixed driving is a win.

Car behaviors:

• From stop, light throttle gives near full assist for a moment, and then it tapers back to 3-6 bars @ 1600-2000rpm. I like to goose it off the line to max the assist and then hold 2000rpm.
• 3000rpm+ acceleration generally gives full assist, particularly when accelerating.
• Usually only gives 3-6 bars of assist when maintaining speed going uphill even at higher rpm/load.
• 4-7 bars is normal operating range. The closer to middle, the longer the battery lasts. Mine tends to stay 5-6 most of the time but will creep up to full slowly (many minutes) with steady speed cruise.
• 45mph straight and level with cruise control should get you about 65mpg optimally.

 

Hey Keith,

I have another set of questions for you. I need your wisdom please. So, despite what you said, I still went on a hunt for better MPG. I got an alignment because it was driving me nuts the car wouldn't stop pulling to the left. Upon taking it to Firestone, they discovered that my 12v was bad. I hear via forums, if your 12v is bad, it can affect your gas mileage. So I waited until the next day, (today) and went to Honda to buy an oem battery because some people here claim it's the ONLY way. Well after taking my car out of the shop, I saw my numbers slowly creep up. Not amazing, but WORTH NOTING FOR SURE. I wanted to keep the ball rolling. I had sold my second car earlier today, so I had some cash left over to do the CVT FLUSH. Upon leaving the dealership I reset my odemeter trip meter expecting some SUPERB numbers, but to my surprise (yes it was cold start) my first 1 miles of driving gave me 19 mpg city, excess coasting. I have never got that low on ANY cold start. I kept on driving today, two things I have noticed. 1, my IMA is taking forever to charge. Maybe it's in my head, but I feel as if it takes a lot more regen to keep it topped up. It's like my car likes to stay in the four bar range, and that's fine, but I also feel my car is getting slightly greedy with assists which is affecting my mpg. I am at a loss man! I felt like I blew all this money to get lower numbers than before! I admit, my numbers have been creeping up the more I drive, but am I not waiting long enough for things to "set in"? Should I just suck it up and wait about a week or maybe even 3k miles before I complain? What's your take? Also I have a bushing that Honda recommends I change which is causing the car the pull left STILL. Also, I have a broken transmission mount that I am getting fixed tomorrow under my extended warranty I purchased for the car. Anyways, sorry for the jumble of info. I hope you can still decipher and help! Thank you for your time Mr. Keith.

 

Oh, I never mentioned that my new mpg is hovering around 37. No where near 39 which what I was closer to before. Also, I forgot to mention that today it was cold enough to hail. But I can't imagine any cold weather here in the San Francisco bay area would be cold enough to irritate the battery right?

 

I have no problem spending more money to get another flush in two weeks if I need to. Also, I plan on getting the valves adjusted and changing spark plugs as well in the next week or so. I don't want to give up just yet. I really like this car!!!!!

 

12V doesn't generally affect mileage, but it can adversely affect the IMA electronics and cause error codes. A VERY marginal 12V that requires constant charging will put a load on the IMA system and potentially affect mileage.

I recommend replacement of the 151R with a 51R for higher capacity. Probably made a dozen posts to that effect on here. Still, OEM is fine.

No more CVT flushes unless the transmission is not performing smoothly. Progress with changing fluid every other oil change.

New plugs never hurt, but they're about $14 from an auto parts store, and there are 8. Use only the NGK or DENSO plugs specified by Honda. DON'T buy them from Honda. $25 each.

Your first mile is almost always going to be pure **** unless it's downhill and you don't need to touch the accelerator.

Alignment issues waste energy. Added friction from constant steering input can notably affect mileage.

Colder weather notably affects mileage from both thermodynamics and battery utilization perspectives. The cylinder charge is more dense and needs more fuel to maintain the A/F ratio, so you burn a little more fuel at colder temps. Additionally, below about 50°F, NiMH batteries are sluggish and high currents can damage them, so the car will use the IMA system less at colder temps.

Before you can make any valid assessment, you really need to know the car's capabilities.

First, confirm that the list of items in post #5 are true for you as well.

Second, COUNT the number of times you see 2 bars on the gauge. If you're getting regular recalibrations, your battery is deteriorated, and your IMA system will be less effective. This can have a massive impact on mileage.

Third, get a good baseline. Pick a 3-5 mile stretch of the flattest road you can find where you can cruise at 45-55mph without interruption.

1. Make sure the car is at full operating temp.
2. Establish your cruise speed, set cruise and allow to stabilize.
3. Reset "B" meter.
4. At end of run record speed and mileage before you lower your speed.

Repeat above steps in the other direction at the same speed.

You will have two mileage numbers. One may be higher than the other to account for slight elevation changes you can't perceive.

Average the two readings. This should represent your baseline mpg potential.

 

You said you are in East of San Fran. Does this have a lot of hills everywhere?

If its like California with a lot of hills, I would guess this would be bad on mileage. The down-hills DO NOT make up for the amount of gas needed to move a 3K lbs vehicle up any sort of hills, especially from a stop.

You may want to take the vehicle to a flat area just for test purposes and see how it does.

In my experience, even with a bad battery I would never get below 42MPG. With a good battery I get 46MPG easily. (of course this is avg because summer I get 50+ and winter 42 even with good battery)