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which 3 cylinder gets the best mileage?
Topic Started: Dec 16 2009, 09:37 PM (1,330 Views)
Dallas


im thinking of doing something potentially dumb again, waste money on a geo. but if im going to attempt to have the fastest metro here (see sig) I also want something that gets wicked miles per gallon (yknow, to offset the costs n all)

all I know is the mk2 hydraulic lifter motors, but from what Ive seen about the older motors, is a better (hemi) head design and better ports. im thinking of building the motor all up too.

I dont even know if the mk2 transmissions work on an mk1 motor? or the mounts? does an mk1 bolt into an mk2 chassis with no work?
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Coche Blanco
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Constructive post below:

I wouldn't worry about it, you are probably going to get a negligible increase in gas mileage when you compare it to a "perfectly running XFi."
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mwebb
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FOG


i dunno about the engine , but
the 1996 and later computers are faster and they use heated 02 sensors , so they get into fuel control sooner -
so

the oem electronics on 1996 and newer 10g engines are going to provide greater efficiency and better fuel economy
but the older bodies are lighter

i do not know the CD for the older bodies but the 1996 and newer is pretty good which may be more important to fuel economy than the difference in mass between old and new bodies

the 3tech economy cam will help no matter the choice
and the singh grooves have been tested and test results show that modification will enhance fuel economy BUT will UNenhance max power output
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Dallas


I am thinking tunable ecu, sorry. all out, but meant for just mpg. see what the highest number is I can get. not many people playing the speed game around here, so I wanna compete this way :D

I would also probably build it in an mk2/3, they look the best imo
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mwebb
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FOG

Dallas
Dec 16 2009, 11:41 PM
I am thinking tunable ecu, sorry. all out, but meant for just mpg. see what the highest number is I can get. not many people playing the speed game around here, so I wanna compete this way :D

I would also probably build it in an mk2/3, they look the best imo

ultimately
a later version of the megasquirt system can be configured to operate with a knock sensor to provide feedback to the ignition timing

and could be configured to provide multi point sequential fuel injection as well.

but
if you do not intend to include at least the first feature in your system , a stock OBD2 system would provide better fuel economy .with less aggravation and frustration , especially if you are operating without scopes and enhanced scan data .
imho
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chads4dr


mwebb
Dec 16 2009, 10:38 PM

i dunno about the engine , but
the 1996 and later computers are faster and they use heated 02 sensors , so they get into fuel control sooner -
so

the oem electronics on 1996 and newer 10g engines are going to provide greater efficiency and better fuel economy
but the older bodies are lighter

i do not know the CD for the older bodies but the 1996 and newer is pretty good which may be more important to fuel economy than the difference in mass between old and new bodies

the 3tech economy cam will help no matter the choice
and the singh grooves have been tested and test results show that modification will enhance fuel economy BUT will UNenhance max power output
1994 old body and 1995 new body have heated o2 also (and other goodies, I don't know if they recieved a new computer though) Heres an the page from my 1994 Factory Service Manual explaining it:

Posted Image
Edited by chads4dr, Dec 17 2009, 12:50 PM.
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Dallas


im confident the stock ignition map on a metro is set pretty conservative, because under normal factory conditions, its pretty difficult to make it knock. even running on old farm gas climbing hills. means theres room to work with, plus I can configure it to alter the afr when I activate the water injection. itll use less gas and run leaner (hotter) but the water will take care of the difference. its just something ive wanted to play around with. run at like 17:1 afr without blowing it up :)
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mwebb
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FOG

1994 old body and 1995 new body have heated o2 also (and other goodies, I don't know if they recieved a new computer though) Here's an the page from my 1994 Factory Service Manual explaining it:

some early systems have heated 02 sensors
ok
but
the OBD2 ECM S operate at faster speeds , they make decisions quicker ,
so they are more efficient at keeping up with changes in operating conditions
===================================================================

i believe that
the system that can operate with feedback from a knock sensor to help manage the ignition timing map will be more efficient and provide better drivability and fuel economy and SURVIVeability
than

an experimental lean burn system that depends on water injection to prevent engine destruction that DOES NOT have a knock sensor or FEEDBACK from a Knock sensor to help manage pre ignition in a tampered with ignition timing map



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