Fuel Economy Tuning Ideas

[S2H]

Foot out of it? Look at the RPMs and % throttle! I was steady cruising at 60 mph and < 2000 rpm.

well...shit..I didnt even look at that..LOL
I just looked to make sure you have the right stuff for MPG...

that sounds like you need to get a better tune on that thing...with your setup I would expect 18-20 avg when cruising on the highway at low throttle..possibly even as much as 22-24 if you do is just right

[tici]

Are ther any drawback changing the DFCO settings? Like overheating the cats?
If it was so simple to gain a couple of MPG why did GM choosed those settings? Mileage is important to them... CAFE, Gas Guzzlers...

[nytoy]

So I went out and got the MPG PID to work, then I tried changing the setting like EC Tune said for the narrow band 02 sensors, and did notice any change in the MPG PID, nor any change on my wideband a/f ratio.

I have ltft and stft's off and in SD mode, would that have anything to do with it?

[S2H]

So I went out and got the MPG PID to work, then I tried changing the setting like EC Tune said for the narrow band 02 sensors, and did notice any change in the MPG PID, nor any change on my wideband a/f ratio.

I have ltft and stft's off and in SD mode, would that have anything to do with it?

if you arent using fuel trims..then you wont notice any difference when you change the O2 stuff....
you have to be in clsoed loop for the O2's to make a difference...

if LTFT and STFT are off then you are basically in open loop....
then you need to change VE/MAF tables to get your desired results

[nytoy]

if you arent using fuel trims..then you wont notice any difference when you change the O2 stuff....
you have to be in clsoed loop for the O2's to make a difference...

if LTFT and STFT are off then you are basically in open loop....
then you need to change VE/MAF tables to get your desired results

Gotcha, what is the general rule of thumb for a/f ratios when not WOT? I'm seeing 14.1 even when 50-70% throttle.

[S2H]

stoich =
gas/petrol 14.7
diesel 14.5
Alcohol/Methanol 6.4
Propane 15.5
E85 9.765
E100 9.0078

shoot for stoich when not in PE/WOT conditions

[nytoy]

wow! I always thought if you were like 80% open throttle and up you should be 12.5. Guess not. Thanks.

[S2H]

Throttle position doesnt have anything to do with it...
its based on load...
the higher the load the more fuel you want(within reason...max rich of gas on NA engines is considered approx 12.5:1)

[nytoy]

Throttle position doesnt have anything to do with it...
its based on load...
the higher the load the more fuel you want(within reason...max rich of gas on NA engines is considered approx 12.5:1)

So when tuning, should I not worry about varying loads and throttle positions? Is there a way to measure load? I doubt my car sees much load because of the weight and gearing (4.10s)

At WOT would it be better to tune for 12.8 NA?

[S2H]

watch your spark tables....
you can see the calculated load there

when tuning you are trying to get consistent data for various cells...whether its VE or MAF or Spark or whatever..the key is a lot of "good data"

[shanekennedy]

has anyone played with torque converter settings to improve fuel economy & if so did you learn anything useful?

[S2H]

has anyone played with torque converter settings to improve fuel economy & if so did you learn anything useful?

you can sometimes get better fuel econmy by making yoru car shift up into a higher gear sooner...go too far and you'll lose fuel economy from the car working harder to get up to speed and having to give it more gas to get there...
sometimes just changing the downshift values so that you stay in gear longer or shorter helps...

its not usually a huge amoung... a buddy of mine who has been playing with his for several months now is reporting a whole whopping 1mpg difference....he's probably spent more gas in testing to find the right values for his car and converter than its worth..LOL

[Dirty Howie]

Glad I found this thread as I would definately like to improve my gas milage as one of my first goals when I get my package.

Having a 402 in a A4 with a torque converter I know I am going to suffer compared to an M6. Right now I am averaging right around 20. If I just cruize on the fwy at 75 I will get 23.5. But this quickly drops the soon as I get on city streets. I do notice that my mpg drops significantly while the car is warming up in the morning......


DH

[S2H]

you need more fuel at a cold startup...henceforth less gas mileage...

on a side note....nice pic...loose the car bra....(just my $.02)

[Dirty Howie]

you need more fuel at a cold startup...henceforth less gas mileage...

on a side note....nice pic...loose the car bra....(just my $.02)

I'll bet my warm up is protracted thus using more fuel than necessary....we will see when my package arives.

The bra is on at track (also has covers for the headlights which were off in this pic.

Here is one with the BRA off but the BRAOD on




DH

[Runn WS7]

Nice...

[Pro Street]

DH how tall is your tuner?She looks very tall!

[Dirty Howie]

DH how tall is your tuner?She looks very tall!

My car is very low .... those are 18x35 tires...there is little tire to fender gap.

She too is "Not a Tuner".......and when she bends over she doesn't seem so tall


DH

[S2H]

My car is very low .... those are 18x35 tires...there is little tire to fender gap.

She too is "Not a Tuner".......and when she bends over she doesn't seem so tall


DH

alright guys...keep it clean and keep it on subjuct please....

[Dirty Howie]

alright guys...keep it clean and keep it on subjuct please....

SORRY !!!!!


DH