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Today, I had to drive from Detroit, Michigan to Montreal, Canada. It turned out to be probably my best ride since I have the car. I accomplished 2 challenges I had set for myself : Reach Montreal without re-fueling, and break the 600 miles for a tank challenge. I did accomplish both. :woot:

Weather was good, temperature was 64 when I left, climbed to 75 in the afternoon, then ended at 58 when I arrived, dry conditions all along. I had already 65 miles done (work the day before), but I was not to re-fuel just for that. I knew it would be a little tight, but feasible to reach without re-fueling.

All along, I adjusted my speed with the changing temperature, having for target to go for max mpg, I was not worried taking a little longer time to reach. At the peak 75 degree, I kept a 62-64mph pace, and when it got in the low 60’, I reduced to 57-58mph. All along, I kept an eye on the instant mpg, trying to maintain it on the 75mpg mark as much as possible. Results : mpg count at the pump : 63.9mpg for the tank average (MID was showing 64.8 ). I did 608 miles with the tank. I’m impressed… and I had fun ! The end part was a “chicken game”, I was not sure how far I would trust the “0 miles remaining”. I fueled about right when it came to 0 (may be 2 miles after). I could have gone a few more miles as I put only 9.5gal.

While driving, I thought I would peak at 62.5, 63mpg on the MID, seeing 65mpg at some point was beyond expectations. I think this is as good as it will get for me with the car in its current setup. The I2 might be able to do a little better, if it’s a little warmer, or if one accepts to drive even a little slower, but for me, these are the lowest speed I agree to drive (safety due to traffic, etc). To do better, I will have to make some mods (lower suspension, better LRR tires, lighter wheels…). For now, it’s a personal record. Still quite a bit far from the I1, but I feel it's quite good for a I2.

I have the car sine a little more than a year now, and I still find ways to have new fun and get impressed… I like it !:mfclap:
 

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63.9 mpg, man that is impressive!

I have a few questions. Did you have the

cruise on or off
Radio on or off
a/c or vents used?
tire pressure
 

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Discussion Starter #3
63.9 mpg, man that is impressive!

I have a few questions. Did you have the

cruise on or off
Radio on or off
a/c or vents used?
tire pressure

Cruise was off all the way. The cruise on the I2 seems to always "push" to gain the target speed. From my experience, it returns 43-45mpg only. To get higher mpg, it seems much more efficient to "go with the road", accept deceleration in slight uphill, get back to speed in sligh downhills, but moreover, lift the throttle to it's minimum point that allows to keep the speed, or very slight deceleration. I some previous posts, Lean Burn was discussed. Lean Burn in the I1 is when the air/gas mix goes very high (24/1)There is no such Lean Burn in the I2 ,but I'm pretty sure lifting the throttle do increase the air/gas mix up to the legal point of NOx emission, therefore giving the additional mpg boost.

I did go with P&G for some stretches, but got tired at some point, and went for a more stable speed.

Radio was on ! 11h drive without music... urk;)

A/C was off all the time. It was the perfect weather, dry, not too hot. I cracked a window open time to time, but overall, was very comfortable.

Tire pressure are at 44psi. I'm still thinking about that though.. may be I should have cranked them up even a little more. It's over the max wall pressure, but... may be 48-50 just for the ride, then lower them for normal daily commute could have returned even slightly higher mpg.

I'm not fully convinced the 63.9mpg is ligit. It's obviously not my usual fueling station... I stopped at the click + added to a second click. I was expecting to put ~9.7gal. The pump gave 9.511. MID was at 64.8, which means 0.9 difference only, which is unusal as several previous fuel up have shown MID about 2.5mpg otpimism. If I had fueled up at my usual pump, it could have been around 62.5mpg for the tank, which is still quite impressive for the I2 (about +45% EPA). Still 608.1 miles with one tank is still what is it, regardless the mpg result.
 

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Thanks! Helpful info. I'm not sure I could drive in 75 degree weather with no a/c the entire time. If it's sunny I start cooking in a car once it gets to 60s.

I'm going to have to try driving more without cruise. The focus needed with the throttle control may keep my mind from wandering so much & from boredom. Though it seems like as soon as I hit the cruise button with econ off, the instant mpg increases and stays up. I'll practice with trips and see what works best for me.
 

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[snip]
I'm pretty sure lifting the throttle do increase the air/gas mix up to the legal point of NOx emission, therefore giving the additional mpg boost.
[/snip]
Since you are referring to I1 lean-burn, I'll chime in. It likely isn't increasing the air/gas mix up close to NOx limits since you have the throttle so close to closed it isn't letting much fuel in the first place because there isn't much air going through. What you are doing though, and it is very beneficial, is preventing the engine from slowing you down through compression as if you were to fully release the pedal. If you want to slow down, fuel cut is great, but if you are maintaining speed, it is the last thing you want to do. It seems you've got the technique figured out. It's better to do this than to burn off your packs power in "EV mode" like I'm reading many people are trying to do here, which is mostly putting power into fighting engine compression, while having the consequence of getting robbed through more MPG stealing regeneration being necessary to get it all back.

You have very good MPG in your I2, it's clear you are doing well, keep it up and you'll continue to run into more tricks!

[snip]
Tire pressure are at 44psi. I'm still thinking about that though.. may be I should have cranked them up even a little more. It's over the max wall pressure, but... may be 48-50 just for the ride, then lower them for normal daily commute could have returned even slightly higher mpg.
[/snip]

I'd say going to the 50psi you said would be a little more than slightly higher MPG. If it was my car, I wouldn't lower them but then again I'm not sure how it affects the ride with the I2, I'm not really picky at all about ride quality though so I suppose I'd do it either way.
 

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filling tires well over max recommended pressure seems dangerous to me. what happens if you hit a shredded truck tire and get a blowout ?
i keep it at 33.
 

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Discussion Starter #7
Since you are referring to I1 lean-burn, I'll chime in. It likely isn't increasing the air/gas mix up close to NOx limits since you have the throttle so close to closed it isn't letting much fuel in the first place because there isn't much air going through. What you are doing though, and it is very beneficial, is preventing the engine from slowing you down through compression as if you were to fully release the pedal. If you want to slow down, fuel cut is great, but if you are maintaining speed, it is the last thing you want to do. It seems you've got the technique figured out. It's better to do this than to burn off your packs power in "EV mode" like I'm reading many people are trying to do here, which is mostly putting power into fighting engine compression, while having the consequence of getting robbed through more MPG stealing regeneration being necessary to get it all back.
Thanks for the clarification MN_Driver. It make sense. Few weeks back, I was trying to figure out if this increase in MPG was due to cylinder deactivation, but we cleared out it was not. The option of "Lean Burn like" capability was a possibility, but your explanation does make a lot of sense. But for sure, controling the throttle is a key factor in increasing MPGs to this level.

For the tire pressure, I have to drive back to "The D" at the end of the week. I'll decide by then if I crank them to 50psi just for the ride... The road is not too bad and fairly "ok" condition. I'm not really scared of a blow out due to potholes, or debris on the road, I might go for the higher pressure.
 

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What you are doing though, and it is very beneficial, is preventing the engine from slowing you down through compression as if you were to fully release the pedal. If you want to slow down, fuel cut is great, but if you are maintaining speed, it is the last thing you want to do. It seems you've got the technique figured out. It's better to do this than to burn off your packs power in "EV mode" like I'm reading many people are trying to do here, which is mostly putting power into fighting engine compression, while having the consequence of getting robbed through more MPG stealing regeneration being necessary to get it all back.
One clarification... The I2 opens the valves during coasting so there is no compression loss. There is still friction loss and regenerative brake losses.
 

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One clarification... The I2 opens the valves during coasting so there is no compression loss. There is still friction loss and regenerative brake losses.
It CLOSES all the valves to reduce pumping loss....

PER HONDA:
"When you're in less of a hurry, there's enough electric motivation to propel the 2010 Insight at city speeds up to 30 mph with the engine off. This transition is utterly seamless because the always-connected nature of the system means the engine is still spinning and the tachometer still registers whenever the car moves. In this fuel-cut electric mode, the Insight's VTEC system switches to a lobe-less round cam that keeps the valves shut to reduce pumping losses."
 

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I've never understood why they would be shut but I've read it over and over again with cylinder deactivation literature with all makes of vehicle. There is air in the cylinders, if you seal the cylinder and try to move the piston it will create either positive or negative pressure depeding on which way the piston is moving. If you don't have at least one valve open appropriate to the piston direction to let the cylinder breathe in and out as the piston is moving, I only see a serious GAIN in pumping losses as you've now got a sealed chamber to create pressure in rather than letting it breathe.
 

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You don't take into account all the volume moving through the intake and exhaust track - that takes more energy than just the sealed cylinder's total volume of negative and positive psi within it's own confinement.
 

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Compression is what slows down an engine though, if you put a vehicle in low gear and cut the gas, it slows down much faster. To seal the cylinders is doing the same thing except you've got both strokes sealed in. There isn't going to be a point where there isn't significant pressure in both directions. How would it take more energy to allow a free flow through the piston than having compressive forces happen inside the engine?
 

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I had read in the 80's that GM closed intake and exhaust valves on some pistons to save gas. The closed valves pistons are like a spring, minimal energy loss. Also it keep the combustion compartment warm for clean restart when power is needed.
 

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... I kept a 62-64mph pace, and when it got in the low 60’, I reduced to 57-58mph. All along, I kept an eye on the instant mpg, trying to maintain it on the 75mpg mark as much as possible. Results : mpg count at the pump : 63.9mpg for the tank average (MID was showing 64.8 ). I did 608 miles with the tank. I’m impressed…
Me too! Well done.
I usually drive a little faster when on the freeway, which is on flat terrain. When I slow to the above speeds I'm able to get similar instant mpg numbers.

... I'm not fully convinced the 63.9mpg is ligit. It's obviously not my usual fueling station... I stopped at the click + added to a second click. I was expecting to put ~9.7gal. The pump gave 9.511. MID was at 64.8, which means 0.9 difference only, which is unusal as several previous fuel ups have shown MID about 2.5mpg otpimism…
I agree the 63.9 figure may be a little high.
(1) It might be that regardless of the number of clicks pumped, that the final fuel level in the tank was slightly less than the fuel level at your prior fillup. If so, the next fillup may yield a slightly too low mpg and greater MID optimism, and a sawtooth pattern on a mpg graph.

(2) Another possibility, is accuracy differences betweem the two pumps measurement of amount of gas actually pumped. ...lets not go there.

(3)In my search to understand the source of the MID software error producing MID optimism I keep coming back to my ev mode hypothesis. This idea was recently strengthened after a recent trip, in which the two fillups were mostly highway driving, including a great reduction in amount of ev mode used and a decrease in MID optimism.

Does your driving for the above fillup represent a big reduction in amount of ev mode used?

(I live in a hilly area and use downgrades, in a terrain sensitive way; to increase speed, regen the battery, use ev mode, or all 3. By doing this I get big increases in mpg tankful after tankful.)
 

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Discussion Starter #16
(1) It might be that regardless of the number of clicks pumped, that the final fuel level in the tank was slightly less than the fuel level at your prior fillup. If so, the next fillup may yield a slightly too low mpg and greater MID optimism, and a sawtooth pattern on a mpg graph.
On the aftermath, it was very difficult to confirm if the fuel up was lower than usual. Over there, I drove quite a bit in Montreal, crossed the bridges several times in heavy traffic. I left for the trip back with less than half tank, and I was quite heavier than the trip in. The tank ended up roughly ½ - ½ city/highway driving with heavier load and still yield 55.7mpg (real count).

Does your driving for the above fillup represent a big reduction in amount of ev mode used?
May be a less ev than usual, but I still used a good amount while stuck in some traffic zones (Toronto + some repair zones). Cannot confirm your theory yet… sorry ;)

I checked weather underground for that date for a couple locations (Kingston & Waterloo Ontario) and it looks like you had a nice tailwind. I'm still impressed that you got mpg in the 60s!
Yep, did notice that. Bit after Toronto I saw some flags indicating a tailgate wind. It did not seems very strong though just enough to lift the flag, but your finding seems to indicatre it was quite noticeable. It was surely enough to give a little mpg boost, I'd take whatever help mother nature wanted to give me :D Between Port Huron/Sarnia and Toronto, there was no wind at all (or I didn't notice any...). It was not helping the mpg boost, but surely not killing it.

One thing though, for the trip back, since I was heavier loaded, I tried a little higher tire pressure to compensate. I liked the drive and I kept them there since… I do see a difference. It seems these Dunlops like high pressure. There is a noticeable rolling difference. I am above max side wall pressure now, so I wouldn't officially recommend to try, but....

Since this trip to Montreal, 3 factors have changed : 1- It’s warmer outside (in the 80’s almost every day), 2- I’m driving with higher tire pressure 3- I’m running with Mobil 1. Most probably all these factors are contributing, but I don’t find it hard to keep my tank average above 60mpg. I start to feel it’s possible to go further than 608 miles… I'm half way in the tank since I fueled up after arrival and I'm at 350 miles, same number as I had in the trip. I’ll challenge the distance soon !:D
 

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..I tried a little higher tire pressure to compensate. I liked the drive and I kept them there since… I do see a difference. It seems these Dunlops like high pressure. There is a noticeable rolling difference.
I noticed the same thing when I went from 33 to 36 along with a much firmer ride. I got used to it and then went to 38. Ride and rolling resistance wasn't that much different but the mpg went up. I recently went to 40 psi. Mpg has gone up again, ride feels borderline too firm, but I noticed a big reduction in roll resistance. I'm much much more careful now to go slowly over bumps in the road, or to steer around them.

Today the Blue Bird flies into its 2nd year of ownership. Fuelly mpg for the year is 50.1, meeting my goal of getting close to our I1's 55mpg yearly average. I attribute half of the improvement in that figure over the EPA overall figure of 43 mpg, to driving style / technique, and the other half to higher tire pressures.

So yeah, I look for ever higher mpg's passing through the Purplegate...:D
 

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I had read in the 80's that GM closed intake and exhaust valves on some pistons to save gas. The closed valves pistons are like a spring, minimal energy loss. Also it keep the combustion compartment warm for clean restart when power is needed.
The infamous Cadillac 4-6-8 - an idea that was ahead of it's time - unfortunately GM had a recall that rendered the system inoperative to fix all the problems they were having with it...
 

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The stretch between Detroit and Toronto is very flat, the stretch after Pickering varies with quite a bit of hills, and once you get past the Brockville, it gets flat-ish again. You'll find most of your fuel consumption between Toronto and Brockville.

As a suggestion you might want to use the 3 finger rule for all your fill ups, 3-4 fingers from the nozzle tip rule, it rules up a lot of the pump errors.
 
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