Can't Get Good Fuel Economy - 2008 Civic Manual

[whatjigg]

At the end of the day, for me, this is less about the money (although it may sound like it above) then it is simply matching or beating the EPA FE.

[Christ]

If you don't care about check engine lights, you can jump the Vtec solenoid so it's on constantly. Only thing about that with OBD-2b is that it might throw the ECU into limp mode (not taking input from other sensors, running on basic maps.)

On OBD-1 models, you can just put a jumper in the Vtec solenoid to run it all the time, and as long as it's not throwing the voltage back to the ECU, it won't activate the CEL.

Further on, with OBD-0 Vtec setups (one-wire Vtec modding) you could leave it active as long as you want, b/c the ECU doesn't check for Vtec solenoid signal, so it won't throw the CEL.(except the OBD-0 B16 engine)

Probably just random loose knowledge that doesn't apply, but there it is.

Consequently, I kinda wish I had OBD-1, so I could use the ScanGauge... I have a non-OBD car, so it's out of my reach... at least w/o a jumper harness and a new ECU.

[KJSatz]

Well for one thing, you are beating the hell out of the (US) EPA, which is 26MPG city, 34MPG highway, 29MPG combined. The Canadian mods might improve that by a mile, but not much more. Converting those Canadian estimates to MPG gave me 32MPG city, 43.5MPG highway...even larger than the "Old" (US) EPA rating for the 2006 and 2007 Civics, which were 30/40 for AT and 30/38 for MT. I think if you really started driving like everyone else in Ottawa, you fuel usage would increase a lot. If you think what you're doing isn't working, try it for a tank.

As for the utility of a ScanGauge, again bearing in mind I myself do not have a scan device (though also that I plan on getting one in the future), I think there would be uses. Instead of spending a whole tank driving like everyone else in Ottawa, you could just do it for several miles and see the difference. You could also use it to tell if you are in that "fuel-efficient mode" (needs a name) by monitoring MAP. Plus just being able to see what works and what doesn't as you do it removes the ambiguity of only getting information every fillup.

And I guess I did take some benefit from the inflated dollar...sorry Honda screwed you like that!

[Christ]

Can we call the "fuel-efficient mode" Vtec? I mean, that's what it is... it's called the Vtec crossover by Honda. Unless you have some creative name for it.. something cooler than "Vtec mode"...

Kinda sounds like Depeche mode.. I personally don't like it.

How about "frugal mode"... or "fuel-responsible mode". They're not cool, but they're at least honest.

[whatjigg]

it's called 'lean burn' mode elsewhere quite a bit, but nowhere is it consistently given a name

I probably will end up buying a scangauge2, just to see and get the instant responses as driving habits are adjusted. If it proves fairly useless to me or I don't get too much more out of it I'll just return it. And i am very interested in being able to monitor this 'MAP' setting on such a device. How does that work?

The US version's price was quite a bit better, and I did in fact find a dealer in Washington who was willing to hand out sick deals to Canadians along with some weird work-around for warranty. However, it really wasn't worth it for the civic as it would in fact cost more to import, only really the higher end accord's or more expensive vehicles were worthwhile. Either way I'm very happy with the civic, wonderfully little car! Btw, best product for cleaning interior is "303 Aerospace Protectant". Doesn't turn the interior into ultra shiny dash w/ greasy feel. It cleans and protects, leaves interior looking/feeling like brand new car. People constantly tell me they think the car's brand new. (nighthawk black pearl paint)

As per US/Euro mpg estimates, they really just confuse me. I never know which one companies/people are using. L/100km is simpler for me.

Christ - i don't really understand/know what you're trying to say or recommend, do you think you could maybe rephrase this in layman's terms? Are you saying that there's a potential way I could force the car semi-permeneantly into this 'lean burn' mode or have i totally misinterpretted everything?


Oh and anyone have any ideas/opinions with respect to resetting the ECU?

[Christ]

Originally Posted by whatjigg

it's called 'lean burn' mode elsewhere quite a bit, but nowhere is it consistently given a name

I probably will end up buying a scangauge2, just to see and get the instant responses as driving habits are adjusted. If it proves fairly useless to me or I don't get too much more out of it I'll just return it. And i am very interested in being able to monitor this 'MAP' setting on such a device. How does that work?

The US version's price was quite a bit better, and I did in fact find a dealer in Washington who was willing to hand out sick deals to Canadians along with some weird work-around for warranty. However, it really wasn't worth it for the civic as it would in fact cost more to import, only really the higher end accord's or more expensive vehicles were worthwhile. Either way I'm very happy with the civic, wonderfully little car! Btw, best product for cleaning interior is "303 Aerospace Protectant". Doesn't turn the interior into ultra shiny dash w/ greasy feel. It cleans and protects, leaves interior looking/feeling like brand new car. People constantly tell me they think the car's brand new. (nighthawk black pearl paint)

As per US/Euro mpg estimates, they really just confuse me. I never know which one companies/people are using. L/100km is simpler for me.

Christ - i don't really understand/know what you're trying to say or recommend, do you think you could maybe rephrase this in layman's terms? Are you saying that there's a potential way I could force the car semi-permeneantly into this 'lean burn' mode or have i totally misinterpretted everything?

MAP = Manifold absolute pressure.. the figures change when you hit Vtec crossover point, so it will be displayed and obvious to you.

US is always MPG, Euro is what you're used to.

What I was suggesting might throw your ECU into open loop mode... i.e. make you get crappy fuel mileage, and have a 3k RPM fuel cutoff point... it's called "limp mode" for a reason

You can disregard that information, it won't work correctly for you.

[whatjigg]

well thanks anyhow, i appreciate the information, and yes what you say does make sense, as the 1.8L VTEC can operate in 'lean burn' mode only between 1000-3500RPM

I think i will go and pickup a SG2 tomorrow/monday, depending on when their open. I'm more and more curious as to the results I'll see.

[KJSatz]

Lean burn is different. Civic HX and VX of old, and the current hybrid's ICE, have lean burn. That actually changes the ratio of fuel to air in the mixture. What our R18 does is partially retract some of the charge so that less of the mixture is used. I think it's pretty clear in the second link in my first reply here. Also, calling it VTEC would be incorrect. If you are in a lower load situation from 1000 to 3500RPM, you will probably be in VTEC, but you won't be in this weird thing unless you're in especially low load. At least that is the way I understand it; if they are activated only with each other, I am mistaken.

[fanamingo]

Originally Posted by KJSatz

On a ScanGauge or the like ... monitoring the MAP sensor will tell you (it jumps down if you're in and jumps up if you're out).

KJSatz, can you elaborate on the output of the MAP sensor (typical values)? I had tried monitoring it a few months ago, but was never able to see a distinct jump that would show when i-VTEC was engaged/disengaged.

[fanamingo]

Originally Posted by KJSatz

What our R18 does is partially retract some of the charge so that less of the mixture is used. I think it's pretty clear in the second link in my first reply here. Also, calling it VTEC would be incorrect. If you are in a lower load situation from 1000 to 3500RPM, you will probably be in VTEC, but you won't be in this weird thing unless you're in especially low load. At least that is the way I understand it; if they are activated only with each other, I am mistaken.

Reading through your first link above, I think the techniques for reducing pumping losses are part of i-VTEC.

With the R18A SOHC i-VTEC mechanism, Honda's R&D engineers introduced the idea of controlling the amount of air entering the combustion chamber via other means instead of the throttle butterfly. This is done via a combination of both valve timing and an exploitation of the property of the 4-stroke cycle and a new Drive By Wire (DBW) system.