Tweecer for Mileage?

94-302-vert · Mar 4, 2008

My car gets "OK" mileage... I get 18-18.5 MPG... That is running premium because my EGR is defunct so the computer puts in a TON of initial timing and I also know that the car runs rich. My drive is basically all highway, 20 miles to work at 55mph (country road) then 75-80 mph for another 30 miles on the highway...

Seems to me that at $3.30 a gallon for premium, vs $3.05/gallon for regular, and 400 average miles/week a MPG improvemnt of 5% with running regular (~7% cheaper) will pay for itself very quickly.

Does this seem reasonable? I figure I can turn off the EGR and then if I need to I can lean it out or change timing.

Would I need to invenst in a WB for what I am trying to acheive as well?

Thanks for any/all input on this as I can't seem to find the answer.

vristang · Mar 5, 2008

94-302-vert said:
My car gets "OK" mileage... I get 18-18.5 MPG... That is running premium because my EGR is defunct so the computer puts in a TON of initial timing and I also know that the car runs rich. My drive is basically all highway, 20 miles to work at 55mph (country road) then 75-80 mph for another 30 miles on the highway...

Seems to me that at $3.30 a gallon for premium, vs $3.05/gallon for regular, and 400 average miles/week a MPG improvemnt of 5% with running regular (~7% cheaper) will pay for itself very quickly.

Does this seem reasonable? I figure I can turn off the EGR and then if I need to I can lean it out or change timing.

Would I need to invenst in a WB for what I am trying to acheive as well?

Thanks for any/all input on this as I can't seem to find the answer.

I don't really belong in the sn95 world (I own a Fox ),
But I'll throw some thoughts out just the same...

The EGR in the Fox ecu (A9L,X3Z) only adds .75* of advance when the EGR is active. (I may have read that wrong, but from what I can see... there is less than 1* of advance added when the EGR is functional.

Also,
The ecu should be disabling the EGR function when it sees that the EGR feedback is not within range. This means that the EGR 'logic' will deactivate automatically.

My point here is that you shouldn't have to run premium fuel just because the EGR is not functional.
How much timing are you running now? Maybe back it off a couple of degrees?
Maybe there are some other issues causing the ignition problems???

Some may argue that getting the EGR functional would help to improve your economy

Curious what others have to say
jason

GTA_V6_Mustang · Mar 5, 2008

The EGR's purpose is to lower NOx emissions by lower the combustion chamber temps to below 2500*. Real simple it takes an already burned portion of the exhaust and re directs it into the combustion chamber so that there is a portion of your combustion chamber that will be dead pretty much and effectively lower combustion chamber temps.

Now you are running 93 most likely because like u said your EGR is not working. So your combustion chamber temps are higher and to avoid the dreaded ping 93 takes care of you. Fix your egr and with stock or lower than stock timing(Depending on your set-up) you should be able to run 87. I know i do.

As far as tweecing the car for MPG I dont see why not. That is another reason I am justifying spending the money to get one. To have a highway tune for my long trips to squeeze that extra bit per gallon. However It is not something I recomend without a WB because you need to see just how far lean you are going. But a lot of auto manufactures today use W/B from factory to monitor stoich and lambda. For instance my g/f honda civic has a w/b from factory and during highway cruising can achieve an air fuel mixture of as high as 22:1 getting us that 40+ mpg. Its all in how much time you put into it thats actually critical.

94-302-vert · Mar 5, 2008

I know that fixing the EGR would help things... I just think that $$ is better put towards a tweecer... EGRs for our cars are $$.... At one time I think I priced up the tube and the EGR at close to $200...

GTA_V6_Mustang · Mar 5, 2008

egr valve is 85 bucks at advance. Cheaper if you know someone that works there

94-302-vert · Mar 5, 2008

That is a pretty good price, but that is still 20% of the way to a tweecer without having to buy the egr tube either....

GTA_V6_Mustang · Mar 6, 2008

Get that chit at a j/y then, lol. Or have an exhaust shop fab one up cheap.

divit250r · Mar 6, 2008

GTA_V6_Mustang said:
Get that chit at a j/y then, lol. Or have an exhaust shop fab one up cheap.

I made one up out of copper line, using the factory nuts to help flare the ends onto the EGR and header fittings. Worked like a charm all last year, and it really looks better than the welded-up stocker I had in there.

Scott

94-302-vert · Mar 6, 2008

I have to say that I am not going to dive in and fix my EGR.

I looked into it. I need an EGR (mine is bad), I need the EGR hose, AND my EGR is not getting a vacuum signal from the whatever it is...

SO if I Tweek my car to turn off the EGR and play with A/F and Ignition curves can I increase my mileage by 5-10%?

GTA_V6_Mustang · Mar 7, 2008

94-302-vert said:
I have to say that I am not going to dive in and fix my EGR.

I looked into it. I need an EGR (mine is bad), I need the EGR hose, AND my EGR is not getting a vacuum signal from the whatever it is...

SO if I Tweek my car to turn off the EGR and play with A/F and Ignition curves can I increase my mileage by 5-10%?

u can with a tuner and patience but,with an egr u could pull leaner a/f ratios safely for improved mpg

vristang · Mar 9, 2008

94-302-vert said:
I have to say that I am not going to dive in and fix my EGR.

I looked into it. I need an EGR (mine is bad), I need the EGR hose, AND my EGR is not getting a vacuum signal from the whatever it is...

SO if I Tweek my car to turn off the EGR and play with A/F and Ignition curves can I increase my mileage by 5-10%?

I guess my point was...
The EGR being nonfunctional, should NOT cause timing issues...

HAVE YOU PULLED CODES?

Buying a tweecer to fix a hardware problem would be..........

jason

BlueOvalStangGT · Mar 10, 2008

I have all my old EGR stuff, I removed it because it was an eye-soar and everyone said it was not neccesary, should I put it back in?

vristang · Mar 11, 2008

BlueOvalStangGT said:
I have all my old EGR stuff, I removed it because it was an eye-soar and everyone said it was not neccesary, should I put it back in?

There is still alot of debate on this...

Personally, I think the theory is pretty sound... Higher EGR rates will allow more timing, less fuel (due to less O2 in the mixture), and increased VE (due to throttle opening).

However, most folks don't report a significant change in MPG when installing/removing the EGR system

Theory sounds good, but real world isn't really matching up

My 'theory' is that the Ford programming for EGR is not aggressive enough to come with MPG gains...

I would love to hear what others have to say on this

:Word:
jason

94-302-vert · Mar 11, 2008

I was thinking along the lines of whether or not the 2005+ mustang has an EGR system... I

94-302-vert · May 5, 2008

UPDATE: After deleting the EGR, loading in the agressive timing from tune exchange, and getting rid of the tip-in retard...

My car is now running better than ever on 87 octane and mileage is up to ~19.5... Before tuning I was running 93 octane (due to EGR advance) and I was getting ~18 MPG...

Tweecer for Mileage?

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