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I have been searching around for ways to improve the FE on my new 2010 HI-II. So far, I have ~110 mi and an average of 42 mpg. I am aware that my FE will rise as the car breaks in over the course of the next couple thousand miles.
That said, I live in hilly Vermont, where there isn't a flat road to be seen for miles around. From my house there is about a 400 ft elevation drop over 1 mile on a dirt road, and I have to stop about 1/3 of the way down. My FE is fantastic on the way down, but it suffers on the way back in. I was wondering if there are any specific techniques I can use to get better FE on hills.

Thanks for any advice,

Miles

Stay out of assist as much as you can -- recharging the battery is expensive in terms of fuel usage. When approaching a hill, gain as much speed as you can before beginning the climb. When climbing let your speed droop as you go so that you can maintain a higher instanteous fuel economy. If you have someone behind you'll have to choose a safe lower limit to your speed and then maintain that for the rest of the hill once you reach it.

The most efficient way over a hill is to use just enough energy to get over. I've been known to crest hills with the engine off at less than 5mph. ;)

With a hill that long on the approach to your house, you will be depleting the battery pack. Do whatever you can to fully recharge it early on the next trip out. Then keep it charged and ready to tackle the hill as you come home again.

You might be better off selecting a higher rpm for the hill - better to directly burn a bit more gas than to use up battery charge. That charge then has to be replaced later by burning gas, only with conversion losses in and out of the battery.

The nice thing about living on top of a hill is that the battery pack can fully charge before I even get halfway down to the bottom of the hill. In that case, would it be alright for me to use assist, because the battery will charge on the way back down anyways? Or, will the car try to recharge the battery on the uphill if the SoC of the IMA battery drops too low?

You don't have much choice about using assist. The HI II likes to assist. The key is to not use too much assist. As Sean said, build your speed before the hill and let it sag as you go up the hill. You will have to experiment to find your "sweet spot" for the bottom of the hill, but whatever it is, try to maintain your throttle position all the way up the hill. Lock your foot into a state of rigor mortis. Your speed will drop, but your FE should maintain.

Yes, if your SoC gets too low the car will attempt to charge the battery while you are still climbing. Not good.

Thanks so much for your help, guys. I just have a couple more questions about the Insight II unrelated to actually driving in hills, if you don't mind me asking.

First, on the screen in the MID showing the power sources for the car, if the icon of the gas nozzle is not illuminated and there is no arrow going from the gas nozzle to the car, how much gas is the combustion engine using?

Second, is a moving key off Forced Auto Stop even viable in the HI-II? If not, is there another way to do FAS in the HI-II? Or, does the engine turn off anyways when it's not using the combustion engine as a power source? Or, will the transmission break if a moving Forced Auto Stop is used in the HI-II?

Finally, can the CVT in the HI-II be re-engaged at speed?

Thank you very much.

Miles

Hey there guys,

The weather up here is starting to get a little chilly, and every night it's down to about -5 degrees C or cooler(~23 F). On my trip, I have a nice long section that I can usually get over 60 miles to the gallon on, but recently I haven't been able to engage a glide because the engine is still heating up. Is there anything I can do to get the engine to heat up faster? I was considering the "engine blocking" where you put insulation in the front vents, but is that effective?

Thanks,

Miles

Absolutely worth it. I have my grille blocked in anything less than 60-degree weather.

You would probably do well with a plug-in block heater, considering your location.

I've tested this, and it is not worth it to try and warm the engine faster just to get better mpg later on. There is a direct (inverse) linear relationship between engine temperature and final trip mpg on my short commute. That is, the colder the engine when I'm done, the better the mpg for the trip. This may require dwg (bundle up), though, since the heater won't be up to doing much for you.

Gravel or dirt roads are a killer. I have faced that often with a friends house where I often visit. In addition to the increase in rolling resistance, you have some traction slippage which also reduces your efficiency - I think.

With a lot of coaching by Wayne, I've come to believe that assist is always a bad situation. I'd probably experiment with using the lowest possible gear to stay out of assist. But your situation is definitely a difficult one.

Sorry, I forgot that all the Insight II have CVT - at least I think so. In that case you are stuck with the gearing that the computer gives you. You might experiment with different speeds for your dirt road climb, and see which speed gives your the least assist. Bottom line is I don't really know the car well and should probably not be offering advice ;-)

HI mgyucht;

Driving on seriously hilly roads always presents a good challenge since in the end it depends on the steepness and duration of the climbs.

However, while your strategy should vary depending on the type of climb, the following is approach I recommend:
- On short climbs, (and as Sean and others correctly stated) build a bit of extra speed before the climb and let the speed bleed slowly while minimizing the accelerator pedal input. You do the same for long climbs that are not too steep.
- On long climbs over varying levels of steepness, start with the previous approach then switch the transmission lever to S and moderate your accelerator pedal input so as to induce the lowest levels of assist possible. If you have paddle shifters pick a lower gear setting. Yes, the engine noise will go up, the FE will take a bit of a hit and you will still use some assist but it is often a better FE approach than depleting the pack entirely.

Blocking the front grille will do wonders for your Insight II since unlike the HCH-II, it will allow for improved fuel economy even at lower ambient temperatures. Remember that with the later Gen IMA platforms, the ambient temp is a major determinant of your FE in addition to the engine temperature... so blocking the grille properly does wonders for you.
An EBH is also a must have if you want the best FE possible.

Finally, when the MID does not show an arrow from the gas nozzle to the ICE then the gas engine is not using any fuel at all. But since that means you'll likely be running in electric, just make sure that you keep the arrows from the battery to a minimum as well. keeping an eye on the charge/assist needle and ensure that it does not rise much above the center level mark will help a lot too.


Cheers;

MSantos

Hey,

Thank you guys very much. This is exactly what I needed to know. What would you suggest for blocking the front grille? what material should I use? I noticed in another article that 3/4" pipe insulation works well, and I'll give that a shot as soon as I can get my hands on some. I'm not sure how soon I will be able to get my hands on an Ebh, though.

Also, PaleMelanesian, you brought up an interesting point. For the longest time I've been trying to find out the best way to defog the front windshield, if cold or warm air is better. I'll experiment with Dwg and test it out a bit. It makes sense that you'd want to equalize the inside and outside temps. I find that after workouts the windshields fog up when I get in the car. Thanks for the suggestion.

The other day, I finally pumped up my tires to the often-suggested standard of max PSI - 2 for the front two tires and max PSI - 4 for the back two tires. Interestingly, the car came with two different kinds of tires with two different maximum pressures, so I just used the max embossed on each tire. This strategy works on all cars, right? not just hybrids?

Thank you all very much.

mgyucht

EDIT (7:48 PM 11-29-09): MSantos, I tried using the S transmission position, but I was having a tough time reducing my assist. I assume that it's something that takes a bit of practice, just like the rest of hypermiling? Also, if regen starts up, what can I do to bring that back to normal? I do have the paddle shifters, FYI.
For most of the long hills that I go up, there is a steady decline right after, so I can regenerate enough to recharge the battery basically full there. So, if I go up a hill that would cause the battery to regen (a longer/steeper one), I can shift it back into the Drive position as I approach the peak so that I can use the battery again? I know that my wording is a little weird. It's just that, I'm not concerned with having a lower SoC at the top of the hill because I have plenty of opportunity to recharge again on the other side.

I hate to say it, but running the AC is the best way to defog the windows. Sometimes cracking the driver's window helps, though.

Cool, thanks very much.

Sorta adding onto this, does anyone know the specific engine temperature states for the Insight II? I was wondering because I have a long ~2 mile segment that I should be able to glide the entire way but I'm having trouble inducing a softglide; it either turns the regen on about 2/3 or it just coasts with the engine on. Recently, I've just thrown the transmission in Neutral for the whole way, but I could easily get close to 15 mpg better on my trip if I could turn the engine totally off. By the time I get to the beginning of the segment, the cold engine temp light is off, but I can't do a soft glide.
This has urged me to consider the following: would putting the transmission in N and turning the car engine off (backing the key back to IG-I then turning it to IG-II) at speed harm the car? Or, should I just try to get my hands on an EBH?

Hi Miles;

No, placing the transmission and neutral and re-powering the car back up with the engine off is not going to hurt the transmission.
However, once you power the engine back on, do make sure you give the transmission the time it needs (1-3 secs depending on temp) to match the speed and RPM before you go for the accelerator pedal. Please remember that the CVT solenoids and valves will function more slowly with lower temperatures.

Optimal soft glides on the HI-2 are tricky and requires quite a bit of practice... but they are definitely achievable with a flexible and steady foot.
In the other hand you should also try the more full-proof FAS glide and see if that nets you as much benefit as it does for many of us. I am not really advocating one over the other, but instead I am suggesting that both should be part of your toolkit since they both have advantages, and disadvantages. In the end though, a FAS glide is still best if you are not willing to hone in your soft gliding foot. I have to admit that it took me quite a while to get it going on the HI-2, but now I think I got the hang of it.

I'm still in the process of producing a preliminary temp transition map and so far the HI-2 looks way better than what we've known of the HCH-2. If I were you, I would leverage all I can in terms of grille blocking and even a block heater as a way of making it even sweeter. In any case, that blue engine temp dash light is your friend. Keep an eye on it and as soon as it turns off it is time to play. If you block your grille you'll player sooner and longer. :D


Regarding your past email... which I sadly failed to respond to:

Placing the transmission is S does not completely suppress electric assist but it does make it easier to use less of it. With this said, this too is still not enough for those of us who would like to use no assist at all.

As we have said before, using S has its benefits but only if used strategically and for the right reasons. Using it while accelerating and at speeds below 25MPH in reasonably flat grades seems to always produce the best results. Above 25 MPH, I would switch to D ASAP.

In climbs, I would stay off of S for as long as the D setting can still allow for minimal speed bleed with minimal to no assist. But as soon as it becomes necessary (speed bleed rates too high) I would kick the S setting in without hesitation at least at any speed below 40 MPH.

Cheers

MSantos

Hey MSantos,

Thank you very much for such a prompt and thorough reply. This will really help me with my endeavors in hypermiling.

I think that the winter gas has hit Bennington now, and I've lost about 6% on my fuel economy, but I'm still working on perfecting my routes and improving my softglide. I've heard that having the car off in motion, even while in neutral, can be deleterious to the transmission because the mechanisms of the transmission are not being lubricated because the pump powering that system is itself powered by the engine. However, I'm assuming that this only affects cars with manual transmission and automatic transmission because I've never seen it applied to cars with a CVT. I'm sorry, but I just really want to make sure that leaving the car engine off and the transmission in neutral while moving is not going to damage the transmission. If anyone knows why CVTs aren't damaged by this, I'd appreciate it if they noted it.

As a side note, I've seen times (infrequently, but it happens) when the gas engine isn't being used to power the car but the fuel economy isn't infinite. I suspect that this happens generally from a cold start.

About the FAS glide versus NICE-on:
I've been thinking about how to use both of these techniques together, but how to balance them I'm not sure. I know that both techniques have their own benefits. The only difference between these two techniques is that the engine is off in an FAS but is on in a NICE-on. Would it be better to use NICE-on during warmup to heat up the engine but to use FAS when the engine is hot because it doesn't take much to maintain the engine heat? After all, the engine block is such a huge thermal mass...

The outlook for getting my hands on an EBH has improved, somewhat. I think that I should have one by New Years.

Thanks again for all the beneficent advice,

Miles

I can't answer for the CVT internals, but the MT is lubricated by the gears splashing oil in the bottom of the transmission case -- that's why they can be FAS'd without issues.

Perhaps the CVT uses a similar splash lubrication since it is (simplistically, anyway) a pair of cones with a belt on them?

Yeah, I guess it's not very important in the whole scheme of things, just as long as it works.

While driving the other day, I encountered a situation where FAS would be a nice tool to have: when coasting on a slight downhill without touching the accelerator but the gas engine still being used to power the car. I wasn't paying complete attention, but I may have had the defroster for the front windshield on, possibly preventing a transition to electric-only power? I'll try driving over the same and similar areas tomorrow and turn off all electricity-using accessories that I can (stereo, defrosters, heat, etc) and try to maintain a soft-glide.

Also, this may provide insight (haha) into the mechanism of the CVT in the car: http://www.insightcentral.net/encyclopedia/encvt.html
I haven't taken a thorough look at it yet, but I will when I can find the time.

From the linked article (which describes the CVT in the 1st generation Insight, though I doubt the design has really changed much since then):

Lastly, this set-up allows for the transmission to be towed. When the engine is stopped, the input from the tires is locked out by the final gear and the driven pulley.

Looks like you are good? Check your user manual to see if it specifies 4 wheel towing capability just to be sure.

Here's the page on towing from the manual:

If your vehicle needs to be towed, call a professional towing service or organization. Never tow your vehicle with just a rope or chain. It is very dangerous.
There are two ways to tow your vehicle:

Flat-bed Equipment - The operator loads your vehicle on the back of a truck. THIS IS THE BEST WAY TO TRANSPORT YOUR VEHICLE.

Wheel-life equipment - The tow truck uses two pivoting arms that go under the tires (front) and lift them off the ground. The other two tires remain on the ground. THIS IS AN ACCEPTABLE WAY TO TOW YOUR VEHICLE.

If, due to damage, your vehicle must be towed with the front wheels on the ground, do this:

1. Start the engine.
2. Press on the brake pedal. Move the shift lever through all its positions.
3. Shift to D position and hold for 5 seconds, then to N.
4. Turn off the engine.
5. Release the parking brake.
6. Leave the ignition switch in the ACCESSORY (I) position so the steering wheel does not lock.

There is a little notice after it:

With the front wheels on the ground, it is best to tow the vehicle no farther than 50 miles (80 km), and keep the speed below 35 mph (55 km/h).

I think that I have hope in the FAS, just as long as I don't go over 35 miles per hour. The only thing is that it's not like towing because I'll restart the engine after the FAS. So, does this seem like it's gonna work?

Here's a copy of the manual:

https://techinfo.honda.com/rjanisis/pubs/om/A2MA20/A2MA2010OMA.pdf

The text is from page 412 in the manual, which corresponds to the 418th page in the pdf.

Sorry about the big text.

It sounds to me as though you'd be fine -- the procedure listed appears to be getting the internals up to oil pressure (which you'd already have done by driving it). That note to leave the ignition in ACC is also not something to worry about as you'll have it back in ON position after the engine stops.

Does anyone else have any input?

35 mph / 50 miles is the same as what's in the owner's manual in my Odyssey. (and wayne's MDX, for that matter) I think you're good to go. You probably are fine if you exceed 35 for a brief period, considering that you are not going to be FASing for 50+ miles at a time. ;)

...You are not going to be FASing for 50+ miles at a time. ;)

Maybe in another life... We can dream.

Hey, thanks for all of the advice. It has really helped with my economy, especially since the weather is getting really cold, and the engine takes much longer to warm up. I have one last question: if the car is running on the ICE without the accelerator being depressed at all, how can you get the engine to switch to electric-only?

Hi guys,

Sorry I haven't checked in for a while; I've been really busy over the past couple weeks. I've had my snow tires on for a little while, and my economy has plummeted to about 42 mpg, as I figured it would. However, I did notice something that may be useful for driving when the engine is still cold.
When I'm starting to head on a slight downhill incline in Drive while the engine is still cold, the car begins to regenerate the battery. I, on the other hand, want to pick up a couple mph to make it over the next little mound. So, I shift it into Neutral, and my speed picks up a little as the iFCD shows a rise in economy. This has been working for me, but I was wondering if there may be an even more efficient way to work the downhills before I can enter a soft glide.

In regards to coasting downhill, with my HCHII, I'll let up the pedal until the car is coasting with regen and then push the pedal in so that no regen bars show up. This simulates putting your shifter to N without actually doing it. Most of the time, though, I'll let one bar of regen stay just to throw a little charge to the pack and to help warm the IMA system when it's cold.

Jess