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Just an update. I recently upped my tires to 40psi from 35 so I am hoping to see some FE boost in this tank. I’m also recording my daily commute mpg using the trip odometer to avoid distortion from the 65 mile bug. Each trip is about 20 miles and so far MOST of them are in the low ‘50s mpg. :) Seeing mpgs over 50 is somewhat elating but don’t know yet if that really qualifies as “improvement” since I wasn’t monitoring individual trips before and so have nothing to compare them to. The test will be when I fill up this weekend and see if they actually translate into an overall tank mileage of >50. Meanwhile my husband is impressed with last week’s numbers--when he saw 54mpg on the readout one time he's like :eek: what the hell did you do, coast all the way home?

I am still struggling with variability—a couple of my trips were 48mpg, and one 45mpg. I’m sure they were due to “driver variability” because the road conditions, temp and route were the same, but cannot pinpoint what I was doing wrong. I know some days my best efforts just won’t keep the instantaneous steady on the right. Other times the instantaneous obeys my foot but it seems like the trip mpg display is stuck. And sometimes everything’s golden and the instantaneous and trip mpg display (and driver) are aligned with the stars and the car is practically levitating off the road and one trip like that ended at 59mpg. The next day—same route, same conditions—it was 45mpg. Sigh. However I’ve recently realized my battery charge might have been a factor in some of my off-days. I haven’t been particularly watching it till until recently when I caught it doing a regen. That was an eye-opener.

Tarabell - if you complete a tank where all segments were > 50, then it's almost a certainty that your tank will be > 50 as well, unless you're doing things like idling for a long time in the morning, then resetting the tripmeter and driving. So you should see something very close to 50+ for the tank. Another variable will be the amount of gas used to fill it - if one tank was significantly more volume than the other, it may drop you a bit. Finally, the averaging display tends to be 1.5mpg pessimistic (you did better in reality) over the span of a tank. I pretty much know if my tank average is anywhere in the 48.5 range or higher, that I comfortably broke 50 when I hand calc it (and I do hand calc it, even though my car #8661 does *not* have the bug)

W/ regard to variability - I get this as well, especially when I first got the car. Now that I've had some time to learn (some) of its nuances, it happens less - but it still happens. So, don't sweat it. Post back on how you took the change from 35psi to 40 in one shot. I'm bumping mine up, but only by a couple of pounds per tank. I still want to retain some comfort, so you'll never see me going more than about max sidewall.

The forced regen can be a killer. I get two kinds - a 'mild' forced that runs one bar, and lasts a few seconds after I finish an accelleration phase. That one's not too bad - I can still maintain 65mpg or so on the iFCD. Then there's a 'strong' forced regen that takes up 3 bars, and runs a few minutes. I hate seeing those, because it's hard to keep the iFCD above 45mpg.

If you need some charge, driving with your headlamps on should help - I notice that I charge faster when they're on, and that's a known carryover from the HCH-1 and Insight.

I really know what you are saying - these spring days cause lots of variations in fuel economy. Wind & temperature swings.

Seems like the wind is always a headwind or crosswind, both going and coming. And the MPG takes a hit.

This tank started out great - I was working strange hours, left the house at 5 in the morning and didn't go home until 8 at night. Traffic was very light and I could drive for maximum fuel economy.

Now I'm back to the regular grind and normal hours, and heavy traffic. The MPG's have dropped on the last half of the tank - will need a refueling soon. Still trying for an 800 mile tank. I'm going to bump my tire pressures up another notch to see if there's anymore benefit left.

Very good job, Tarabell! I know recently the temps in SoCal have been quite cool. When they are back in the 80's, I know you will see an improvement. your husband may really wonder what's going on with all this high FE stuff?
Yeah, 5 more lbs of air will help, because 5 x 4 tires is, of course 20 pounds. That makes a huge difference in rolling resistance. Consider even going to 44 lbs (max tire rating) if you don't mind the firm ride over bumps and potholes.
Later, Billy.......

Hi Tarabell:

___35 - 40 will move you up the bar a little but it would probably not be noticed in your daily grind vs. the variability you are seeing. Let us get down in the dirt and discuss knocking out some monster segments …

___How many miles on your HCH-II so far? Probably not enough for an oil change but you should start shopping for some Mobil1 0W-20 today as it may be a tough find when the time for an oil change arrives. Taking the pressures up 5 #’s is a start. In a few days, I would take them up to 44 #’s as an absolute minimum like Billy mentioned above. Dan created a neat MPG vs. Tire pressure study with his Prius II last year showing an overall increase of ~ 2.2 mpg’s from 35 - 62 #’s. At the extreme mileage he was pushing during that study, you might expect maybe 50% of that same amount or 1 - 1.5 mpg’s from 32 - 44 +. It’s not much of a savings but every little bit counts ;)

Krousdb - Prius II

62/62 PSI. 98.8 mpg at 77F
44/42 PSI. 97.4 mpg at 82F
35/33 PSI. 96.0 mpg at 86F

___Did you see Phil’s case study - post from a few days ago? Enough detail for all of us to start adding something constructive. Can you give us some detail on the types of speeds, traffic, traffic enforcement (stop signs, light’s, turn lanes) that you have to traverse from stop sign #1 to your works parking lot? How are you parking at work? In a Face-Out near the rear? How are you parking in the evening when coming home? Can you take advantage of any height potential between the road in front of your home and your HCH-II’s parking spot? Anyway to avoid the FE killer short segments with an alternate? How about a Warm-up route for a LS to HS P&G scenario? How are the winds and temps from day to evening? I would start watching weather.com --> your zip --> hourly to get a handle on the winds and temps you will see at a given time in your commute let alone what you are actually seeing from the HCH-II’s external temp gauge. Watch the flags, taller grass, and debris on the side of the road to get a handle on what may be taking a particular hit on any given segment. Headwinds are indeed a killer. Are you “DWL” over any and all small undulations? General and Rabbit Timing with any lights? Taking it very easy with the accelerator and DWB w/ huge buffers if at all possible?

___Lastly, you have to manage the SoC aggressively as running EV will take her out and shoot her when bringing the SoC back up in a forced charge mode. I have been thinking about this for a few weeks and my current thought(s) would be to use EV sporadically if at all to begin with. If you are nearing ½ on your SoC meter, do not enter EV unless its for a pure glide and let the ICE bring her back up when running with a very light hidden charge vs. the light and heavy forced charge as Mark described above. Even if you don’t want to enter the more advanced techniques, a well setup HCH-II is worth 60 - 65 mpg without the tricks in my very short time behind the windscreen?

___Good Luck and let us know about your personal case study - initial data.

___Wayne

Tarabell - if you complete a tank where all segments were > 50, then it's almost a certainty that your tank will be > 50 as well, unless you're doing things like idling for a long time in the morning, then resetting the tripmeter and driving. So you should see something very close to 50+ for the tank.
Well that's logical of course but I guess I left out the minor detail that my husband uses my car several times a week each morning for a 8 mile round trip to his health club, and I also occasionally use my car on the weekend. I don't record these segments or factor them in because they're so variable. I can keep my car in the high '40s in the city. My husband is a pretty conservative driver but usually brings back my car with the mileage in the low-to-mid '40s range. So these little trips will be a hit on my '50s average but I'm hoping not too bad and I figure he's warming it up for me in the morning.

Post back on how you took the change from 35psi to 40 in one shot. I'm bumping mine up, but only by a couple of pounds per tank. I still want to retain some comfort, so you'll never see me going more than about max sidewall.
I have to say I could not really detect much of a difference from 35 to 40. I like a firm ride anyway. So I have no hesitation bumping them up some more. Just will have to be more careful of the potholes from the recent rains.

The forced regen can be a killer. I get two kinds - a 'mild' forced that runs one bar, and lasts a few seconds after I finish an accelleration phase. That one's not too bad - I can still maintain 65mpg or so on the iFCD. Then there's a 'strong' forced regen that takes up 3 bars, and runs a few minutes. I hate seeing those, because it's hard to keep the iFCD above 45mpg.
I think that's what I saw just the other day--one bar on while I was pushing the gas, but it lasted about 10 minutes -- then the charge is up to normal again. The iFCD refused to budge over 50mpg while it was going on. I think I had the stronger kind of regen last week.

Xcel I will get back to you with more details but I'm having a hectic moment and it will take a couple days.

Hi Tarabell:

___Take all the time you need as your HCH-II is still breaking in and you are just starting to fire on all cylinders. Wait until the first time your husband gets in and sees 70 + mpg’s on the Trip A aFCD! I think he might even start paying attention to his driving technique … or you won’t allow him to drive your car for that much longer :D

___Good Luck

___Wayne

Xcel I will get back to you with more details but I'm having a hectic moment and it will take a couple days.
tarabell;
Was reading your FE here and just wanted to say, Great: :D

I filled up this weekend and my tank average only came to 48.7. So rats I didn't break 50mpg on this tank though I did >50mpg on most segments, and even started breaking the 60 mark towards the end of the 2nd week. But it's clear those <50 segments dragged my average down--mostly coming home. I'm pretty sure that drive is challenging me because it's a slight uphill grade over 18 miles.

Mileage data for last two weeks: format is MPG/degrees F
Each segment is about 19.5 miles.
Red = :( mileage
Green= :) mileage

Week of 3/20:**MON*****TUE******WED*****THUR*****FRI
to work*******48.4/50***51.6/45***54.5/47***52.9/54***50.2/53
to home*******59.5/61***45.8/61***50.8/63***48.6/72***54.1/70

Week of 3/27:**MON*****TUE******WED*****THUR*****FRI
to work*******53.5/56***50.1/51***60.3/51***61.2/53***57.0/55
to home*******46.0/60***46.3/51***49.5/60***54.8/61***47.5/61

I'm encouraged that today's drive to work seemed to continue my great run last week--got 58.7mpg. I really wish I knew why these numbers jumped--the temperature does not seem to account for it and I didn't think I did anything differently than the first week, but every week my new habits become more and more ingrained it seems.

I am a little concerned about my battery charge and notice now it fluctuates quite a bit, which I never really noticed before. I know I saw the one-line regen Mark talked about, happening several days going home during the second week. Each time the SoC meter would fill all the way up, and I'd think now it's good for a long time, but the next day it would leak back down to 4 bars and then I'd see the one-line regen again. I am hardly using EV with assist at all and thought I was being extremely gentle on the accelerator at stoplights and when merging on freeways. I try to keep the assist within 3-4 bars and the rpms under 2K, so not sure what is going on.

Now I'm hoping I can make the >60mpg morning runs continue and I can get my evening runs consistently >50mpg and bring UP this next tank. I am just staring at way too many butts in front of me on the GH database. :(

My next post will get to some of Xcel's questions/comments.

Tarabell;

I think that you are like doing a very excellent job on your driving to be showing the MPG numbers that you are. :)

Thanks for the encouragement, Tiger, you are a real sweetie.
Billy too...and...okay I better stop here or I'll embarrass half the membership and all the moderators ;)

Last couple sements have been downright weird, so I'll have to post what happened there. But first want to post my commute "case study" as Xcel asked.

How many miles on your HCH-II so far?3470

Probably not enough for an oil change but you should start shopping for some Mobil1 0W-20 today
Sounds like a really excellent assignment for the spouse. :D

Taking the pressures up 5 #’s is a start. In a few days, I would take them up to 44 #’s as an absolute minimum like Billy mentioned above.
I’ll get to 44 but will hold off a just a bit. I’d like to see how the next mileage data set compares with this one without any changes to the car.

Did you see Phil’s case study - post from a few days ago? Enough detail for all of us to start adding something constructive. Can you give us some detail on the types of speeds, traffic, traffic enforcement (stop signs, light’s, turn lanes) that you have to traverse from stop sign #1 to your works parking lot? How are you parking at work? In a Face-Out near the rear? How are you parking in the evening when coming home? Can you take advantage of any height potential between the road in front of your home and your HCH-II’s parking spot? Anyway to avoid the FE killer short segments with an alternate?
Deep breath . . .

Morning segment:
In reverse down short downhill driveway to street. Car usually revs high when starting out – so I basically apply no gas to first stop sign and coast slowly through it to 2nd stop sign. (If spouse has already driven car that morning I have AS, otherwise not.) Left at stop, and go 2 blocks to major street again on one small pulse of accelerator. Turn right, and go straight about a mile with several lights to fwy onramp. Extremely light traffic at that hour. I can time those lights pretty well and EV/glide and DWB most of it.

I take a left onto the fwy onramp which is a short downhill and accel slowly up to 55. Go about 2 miles to interchange which is a nice longer downhill. I coast this part with regen, get in #2 lane, accel to about 60mph, and then maintain speed by DWL rest of the way. There are several more good stretches of downhill over the next 17 miles or so and I just coast these with a little regen if no one’s on my tail, or apply enough gas to get rid of regen if someone is close behind. If speed is falling too much with cars behind me then I will EV/glide with a little assist. There’s a couple brief inclines interspersed and they are a good barometer: If I can coast up them while keeping the iFCD at 75 or above I know I’m going to end up with a great mpg segment.

Then there’s a tight circular interchange ramp to the next freeway. That fwy section is about 5 miles and a slight incline so I just try to keep the IFCD at 50. I coast from the exit all the way to the signal. Turn right at the signal then go about a mile (3 lights) straight to the business park complex. Right turn into driveway, and coast from there semi-downhill all the way to an open lot where I park head-out.

Evening segment:
As you can probably tell my reverse trip is a bit tougher with lots of inclines. Starting up, car is again idling high needing almost no gas to leave complex, but then have to wait at a long light usually without AS. Turn left and go 3 lights in heavy traffic—lots of trucks in this area. Wait at signal behind long line of trucks waiting to get on fwy—sometimes autostop on by then, sometimes not. Depending how many trucks it can take 2-3 signals to finally get on the on-ramp. Bring car slowly up to 55 and stay in the far right lane for 2 miles. This section is a slight downhill and once I get up to speed I can do EV/glide but have to watch the cars crossing in front of me on/off the fwy. Slow to a crawl around the tight circular interchange ramp with lots of cars and trucks to main freeway. Then cross 4-5 lanes of traffic to get to the carpool lane. The carpool lane has very light traffic compared with the fwy but much of it is single lane so I have to go more like 65 due to faster drivers behind me. Within 5 miles or so the rest of the freeway is stopped standstill or heavily congested and I nervously sail by, watching for idiots who might impulsively decide to cross the double yellow lines into my lane. Much of the carpool lane is a very gentle, lengthy incline and I’m struggling to keep the iFCD >50 as much as I can.

Finally carpool lane ends and I have to cross 4 lanes back to the right. I try to time my speed relative to the slower drivers to my right and swoop through to make maximum use of coast, then it’s stop and go to the final interchange. This is a steep climb up followed by a steep incline down. Here I will EV/glide w/assist so when I’m going down I have as much headspeed as possible as I’m being dumped into the #1 lane and have to again quickly cross 4 lanes of traffic in order to exit within the next couple miles. Again I time my speed against the other cars and thread my way between them, but the road is level or slightly dipping and I can pretty much EV/glide the rest of the way to the exit. Right turn at exit onto busy congested street. Stop and go driving for 3 signals, but AS works. After final signal is a slight downhill so I can coast into a left turn, get into EV w/assist and that will take me 2 blocks and right one block before coming to (semi-)stop. Continue EV for one block to house and turn right & coast up driveway. Since husband gets home before me, my car is “last in”. So that’s why he uses mine in the morning (and brings it back just as I’m ready to leave for work.)

How about a Warm-up route for a LS to HS P&G scenario?
OK I know this translates as low speed to high speed pulse&glide but not sure what it means?

How are the winds and temps from day to evening?We don’t get much wind in L.A. except January can be a little blustery, or during the Santa Anas, or if you live near the foothills (I don’t). It’s pretty much gentle breezes. Temperature swing isn't as bad anymore, nights stay in the '50s now.

Are you “DWL” over any and all small undulations?
I find it hard to break the habit of wanting to maintain speed up hills. I have to trust that the iFCD will stay in place if I just keep the same exact pressure going uphill as going downhill, but on long hills it’s not instinctive yet. I keep taking my foot off for quick bursts (to yank the iFCD back up) and reapplying it when I should just keep it steady.

General and Rabbit Timing with any lights? OK I think I left my Xcel decoder ring at home . . .;)

Taking it very easy with the accelerator and DWB w/ huge buffers if at all possible? I’m trying hard to. I’m way reformed from what I used to be but still hate it when drivers take my buffer in front of me--and I wish death on drivers who make me brake.

Lastly, you have to manage the SoC aggressively as running EV will take her out and shoot her when bringing the SoC back up in a forced charge mode.
I absolutely need to watch this more now—not sure if it’s a problem or (more likely) I’m the problem. Maybe have to note SoC and what it’s doing in my daily log also?

Tarabell;

I'm Exhausted after reading your 1-day driving segmeant. :)

You are intense. Very serious, I think more so than me.

Hey before I forget, You get 2-Thumbs-Up from me. :D

Hi Tarabell:

___I owe you my best thoughts on your drive. Give me a day or two and remind me to finish it soon.

___So much to do, so little time :(

___Good Luck

___Wayne

Mileage data for last two weeks: format is MPG/degrees F
Each segment is about 19.5 miles.
Red = :( mileage
Green= :) mileage

Week of 4/3:***MON*****TUE******WED*****THUR*****FRI
to work*******58.7/56***55.0/58***54.5/51***60.5/48***58.8/50
to home*******50.9/68***53.7/61***47.7/61***56.8/63***51.8/63

Week of 4/10:**MON*****TUE******WED*****THUR*****FRI
to work*******54.5/53***58.4/54***60.6/53***58.0/55***58.6/59
to home*******51.6/62***54.2/67***53.0/69***53.7/76***50.0/57

This tank's FE = 51.7mpg. Finally--my first tank over the 50 mark!

The variability demon certainly seems to be having less evil effect. I added color to both this data and my prior data to highlight the good vs bad trips, and there was only 1 trip <50 in this tank versus 7 trips <50 on my last tank
I wasn't able to beat 60mpg more than twice however. So I'm gunning for '60s now in this tank.

I am still mainly using DWB and DWL. I use EV w/assist only for the surface street driving necessary at the beginning/end of my trips. Sometimes the car will go naturally into it on a freeway downhill. Most downhills I just try to keep enough gas pressure to cancel any regen. But most of the time there are typically no bars showing--regen or assist. That tiny daily regen I was seeing earlier is much more occasional.

I think recording each trip separately and having daily data to compare has heightened my awareness of differences so I can anticipate them in future trips. The average outside temp has hardly changed from the last tank so that doesn't seem to be a big factor. I noticed two times where my husband left my car in high '40mpgs which made me blink and do a doubletake.

I'm still hoping for any suggestions from the gallery, based on the data dump in my prior post ;)

wow very impressive improvement, imagine what you can do when summer hits. Nice job its good to see people trying everytime they get behind the wheel.

___I owe you my best thoughts on your drive. Give me a day or two and remind me to finish it soon.


I'm back now from a quickie trip to PA and ready to take any thoughts, best or worst. Got my tanks in the database too so consider yourself reminded! ;)

Hi Tarabell:

___And tonight we shall do exactly that … Yes, I am a slacker ;)

___Good Luck

___Wayne

Yesterday I had a "feeling" and grabbed my camera before I left for work. Got a new best of 63mpg and snapped a photo which if not showing up in vBGarage should be in the gallery. Today I thought it can't get more exciting than that, leave the camera at home and of course I hit a new high of 65.5. :D

It's going to be tough pushing the trip-reset button today to go home I can tell you...

Tarabell, you are our hero !!! Congrats !!!

Hi Tarabell:

___Between you and Mark, it is going to be a very interesting HCH-II based summer and I am grateful to have you here! Nice job on the segment. I cannot wait until the hubby gets the no, you take the other car because you aren’t messing up this tank, thank you ;)

___Good Luck and congrats again!

___Wayne

The quest continues . . .

This tank came up to 57mpg and was nearly 600 miles. A decent jump -- and wish they’d been like that since the beginning! I think the increase is mostly due to driving 5mph slower than a month ago, and changing a couple other things. For instance, the carpool lane I take home -- I get lots of heat behind me where it’s a single lane, so now I don’t enter till later when it opens up to 2-lanes. So I can stay at my slower speed and folks can pass me on the left. Every day at least 2-3 Prii pass me in the carpool lane. I also find trucks are actually nice to snuggle up to even if not exactly drafting – 1) it’s like having cruise control on, 2) few cars will want to get between you two, and 3) cars don’t see any point in tailgating you either, as it’s obvious I have nowhere to go. Surf drafting I’ve found doesn’t work well in heavy traffic as I can sense cars around me getting frustrated due to 2 lanes being blocked by parallel vehicles moving at the same speed.

The variability demon is blessing me with more upwards than downwards variability, which is the kind of question I really like puzzling about –i.e., what was so great about this segment? Why did my FE jump so much right here? I know the greyhounds are sprinting off ahead but I’m sort of like the hound dog running behind with floppy ears, nose on the ground, sniffing with joy.

I also think recording segments has been a great focusing technique and a huge help pinpointing trouble spots for me. But now I think it’s time to stop recording the one-ways, aggregate more and just record round-trips. Since I’ve always gotten higher FE on my morning segment than the evening one, the game I now want to play is maintaining my morning FE numbers all the way home. I’ve been hitting high ‘60s on most every morning segment and have started seeing several ‘60s even on the evening segment.

Also I know the 600 mile mark is an easy mark now, which means I should be able to go 3 weeks between fillups instead of 2 weeks. But it’s also going to mean friendly or maybe not so friendly fending off my overly-helpful spouse who feels he isn’t doing his manly duty if he can’t fill up his wife’s car every weekend for her. Reminds me, I made us all walk to the new neighborhood noodle joint the other night for dinner. Of course it had nothing to do with not wanting to ruin my tank with a 4 block drive...nope, nope … saving gas, good exercise, less pollution, it was all those good things.

A few more tanks like this and some of those greyhounds out there should be feeling a cold nose :D

:D tarabell :D

Interesting post from you and it reads like you are really committed to the personal increase of FE. Good-Luck :)

Terry