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my insight:
Manual transmission
112k miles

Just a question for my fellow Insight drivers out there.

At what speeds are you able to get into lean burn and stay in it?

My 2001 I can usually get into lean burn and keep it there at about 50mph. Of course there are days where it will kick in at higher speeds or days where I cant seem to get it for the life of me.

as an example, This weekend I drove about 90 Miles total. both Saturday and Sunday I averaged 80+mpg. This morning on the commute to work. I was lucky to keep it above 60mpg.

How hard is it to maintain your speed when in lean burn? I know you lose some power when in lean burn but its almost like rounding a corner into a head wind that's 20-30mph at times.

I have done the EGR Valve clean using carb cleaner and what not. That helped a bit, but it still feels rough when in lean burn.

I can get into and maintain lean burn at multiple speeds. On one route I can maintain lean burn at 50-55 mph which is all highway and another section with a lower speed limit (45mph) I can maintain lean burn around 35mph. However, if it's raining or you are driving into a strong headwind than lean burn usually can't be achieved.

Try not to focus on the speed you are driving and focus on the FCD display - get in 5th gear and try to hold the MPG somewhere between 100 and 150mpg so you can maintan a respectable speed for the road conditions.

Also, make sure your tires are aired up to atlease 45psi and they are the OEM Bridgestones.

keeping my car at 100-150 is hard to do.

As for tires... Well the previous owner put on some super cheap tires and I don't have the money to buy them just yet. mid October I will be looking for a set of snow tires. and then I will get the OEM tires in the spring.

I have the tires at 43psi all around which is 7psi over side wall. I don't think I'll go much higher. (Yes the max side wall is 36psi....)

You will be quite pleased at how much your mileage improves with the Bridgestone's. I would purchase them asap.

On the last decent length road trip I took, I managed a 78 mpg / 600 mi with speeds typically from 60-70 mpg. You can hold lean-burn down from 70-60 and then reaccelerate. Seemed to yield better results than steady-state at ~50-60 mpg.

At lower speeds, I typically climb hills in lean burn @ 75 mpg and descend at 125+ or engine off.

Correct, new spark plugs (if not recently replaced), a new EGR and proper tires will make lean-burn really rock.

Well, I will check the spark plugs tonight. With the cheap tires on the car I am willing to bet the plugs were replaced with the incorrect plugs....

Hi Mtgeekman:

___Get rid of whatever is on the rims and place the Insight specific RE92’s on her ASAP. That alone is probably 5 mpg gone. Press up to 60 and you have that set. For plugs, do not forget they are indexed and you want to buy the right plug and place it in the right cylinder.

___Lean burn can be seen at all speed ranges but like everyone here has said, above 55, and your chances for 100 mpg are gone. 45 – 55 and you are golden. 35 – 45 and you are looking at 120 +. Some competitive level P&G and you can see 200 + ;)

___Depending on the year, install a clutch switch ASAP.

___Good Luck

___Wayne

Thanks for all the tips. I will get the tires changed out as soon as I can.

Current tires are "Federal Super Steel 715" with a tread ware of 160. Which means these have a softer compound then the competition tires I currently have on my Miata for AutoX racing...

I will replace plugs as soon as I get a chance to check the indexes and order them.

The head is stamped with letters by each plug. Mine is "BBB" and the fool dealership that changed them put "AAA" in.

And $15 a pop, I'm foot dragging to change them out. :)

And treadwear 160 sucks, that's like the Dunlop Direzza Z1 Star Specs my friend just got for his autoX Civic...

I doubt you will be doing much > 1g cornering in the Insight, OEM Bridgestones are best. ;)

I don't have an insight, but on my regular ride I am about to put 4 spares on it. I can get them cheap plus they should be pretty decent even in snow due to them being so thin. quite a bit of weight reduction I'd say.

Ricardo, I'd be extra careful about that. Most spares are significantly smaller diameter (which will throw off your speedo and odo) and only rated for a max of 50mph. I don't know what the rubber compound is but I'm willing to bet it isn't long wear rated.

As for lean burn, I couldn't tell you exactly because I don't go above 55mph unless it is down hill. ;)

I don't use my car for long commutes, and nothing over 50mph either. They would make the odo off but just like I had bigger wheels, I would make calculations of wheel size to compensate. It's just an idea and I may just put really small 13" wheels.

If I go on trips we (my fiancee and I) we take her car, but I need mine as a city commuter...

Thanks for the tip tho.

Maybe my interpertation of detecting lean burn is off...figured a jump in the iFCD from 50 to 75mpg is the hint the Insight is in lean burn.

Maybe my interpertation of detecting lean burn is off...figured a jump in the iFCD from 50 to 75mpg is the hint the Insight is in lean burn.

That's always been my assumption. FCD changes by 25 or so when moving in / out of lean burn.

so then my guess is that it should not be noticeable by the car feeling like its starting to slow down?

I usually notice lean burn because of a drop in power so I have to increase throttle to keep the speed up.

I will keep a closer eye on the TPS from scangauge to determine how much more throttle is needed to keep speed up.

so then my guess is that it should not be noticeable by the car feeling like its starting to slow down?

I usually notice lean burn because of a drop in power so I have to increase throttle to keep the speed up.

I will keep a closer eye on the TPS from scangauge to determine how much more throttle is needed to keep speed up.

The decrease in power is a clear sign of lean-burn as well. If you are tooling along at 50 mpg and it goes into lean-burn, you will lose some power and the iFCD should jump up to 75.

When in lean-burn, the iFCD doesn't drop nearly as fast as you apply pedal pressure. I don't have a SG but it seems like at 60-65 mpg I am using a lot of throttle in 5th, and can maintain 60 mph or so on a flat surface.

well Plugs are ordered and should be on their way to me some time this week.

next question:
while in lean burn mode, should the car feel like it is missing a lot. this seems to get worse as I have to give it more throttle. Maybe I should look at a new fuel filter just in case?

the missing was the reason for cleaning the EGR valve. That helped a bit but did not solve the problem.

Thanks

Hi Mtgeekman:

___It should not miss at all. Wrt the EGR, cleaning sometimes helps whereas replacing it always helps.

___Good Luck

___Wayne

Perhaps non-indexed plugs are the issue? I've read elsewhere that the system is particularly sensitive to spark placement during lean burn -- the whole reason for indexing the plugs in the first place.

Well the plugs I ordered are all B which is what the head is stamped with next to each one. I will replace the plugs and see what happens.

While I was at it, I also ordered the left under panel for the engine since It was missing.

The "miss" is usually fixed with a new EGR. Mine also does it, it's just hard to justify the $200 when I can still break out 100 mpg segments with ease... ;)

Well the plugs should show up at my house on Wednesday.

Other then that I have been practicing a bit more and have my current tank average at 73.3. With yesterdays average being 78.8.

So far today I am at 67.9 with about 8 miles having a 20-25mph head wind.

I am shooting for 75+ by the time I get home.

new plugs are in, they didn't help much.

the old plugs looked fairly good, 2 of them had the nice light brown coloring to them showing the mixture was correct. how ever the 3rd plug was a bit white meaning a lean mixture.

This weekend if I get a chance I will pull off the intake and clean that up. at the moment I cant justify the 160+ for the EGR Valve.

I will take lots of pictures in case any one else wants to give it a shot but wants to fallow along with some one else. ;)

just an FYI...

I read a report that talks about the peak efficiency of the Insight in Lean burn ... turns out the thermal efficiency is as high as 48% which is as good as just about any diesel ... they also found that the lean burn function reduces friction by up to 8%.... thermal efficiency is not total engine efficiency ... but just more data about the benefits of lean burn operation....

The Insight was built for highway lean burn cruising ... and in that role.. it is..

KING

---------------

In case some of the technical minded wanted to know the source paper was:
EPA420-D-04-002
which was done by Office of Transportation and Air Quality of the EPA.
Titled: Advanced Technology Vehicle Modeling in PERE.
the 48% efficiency and 8% reduction in friction come from page 17 of 50.

Just a heads up for a dedicated thread, but My Insight passed Inspection, but emissions problems required me to bring it back on the second day and have no idea how that made a difference. Flunked on evaporator, O2 sensor, EGR, then passed on them. The next day the catayltic converter still flunked but in Texas is was not enough to fail my car overall.

Is this a thread hiijack?: Hope not....I understand the catayltic converter affects lean burn and you can no more just bolt a cat to an Insight than putting on tires that are not like OEM and expect stellar FE.

I also find a big MPG difference in "lean burn" mode, but I don't quite understand how to more consistently get into lean burn mode. Can you guys help?

I also find a big MPG difference in "lean burn" mode, but I don't quite understand how to more consistently get into lean burn mode. Can you guys help?The fuel to oxygen ration in lean burn jumps from 14.7:1 to about 23:1.

I think others will recommend something like this: while staying in a hypermiling mode, get to 35mph as soon as you can and cruise at 4th, usually 5th. If you are in hills, you need to go a few mpg faster than the minimum speed 5th will allow. On a level road in warm weather, 65mph is about the fastest lean burn speed...cold weather, A/C, luggage, hills will take it out sooner.

I don't fully understand what IGN and TPS is on ScanGage, but they may be another hint on when lean burn is activated.

Hope that helps!

A few years back on Gassavers, some of the VX guys rigged up a lean burn indicator using the voltage output from the oxygen sensor. They had a voltmeter display on the dash, that when it went into a certain voltage range would tell them that they were in lean burn. You probably could rig up something similar for the Insight.

In case you haven't seen this article on AutoSpeed ( from April 2008 ) about smoothing out the signal to make Lean burn easier to get into and keep... only a few $ too :)

Giving the Insight a Good Driver (http://autospeed.com/cms/A_110187/article.html)

Hi Basjoos:

___You can see LeanBurn through a cutely coded X-Gauge now ;)

___Imaian, I still think the mod from those guys is junk.

___Good Luck

___Wayne

Anyone know how to add an X-Gage function and detect lean burn?

Yeah!, I'd like to know too

___Imaian, I still think the mod from those guys is junk.


From what I've seen it doesn't seem to do anything that a semi-skilled driver or a steady foot could do without it.

But from my point of view I am pro/in favor of Tinkerers ... Weather the tinkering actually produces real results or is all just illusion... The more Tinkerers we have the better. :D

But to be fare I have not done it myself... and I have not seen much in the way on controlled test results... but I have read the positive feedback from several different people who have tried it.

GAUGE: Lean Burn
->TXD: 686AF10115
->RXF: 044105150000
->RXD: 2808
->Mth : 000100020000
->NAM: LBN
NOTES: (For lean burn equipped hondas)
If the value for LBN = 0 you are in lean burn.
If the value is higher than zero, you are not in lean burn.



This is what I submitted to the XGauge DB in the Scangauge section. have been using it in my insight for a long while now. got it from the insight central forums.