Lean tuning a Hemi for better economy

Greetings all,
I have a daily driven 06 Jeep Commander with the 5.7 Hemi. She has an aftermarket air filter and exhaust. I have tuned her a bit since we got her so her fuel trims are in pretty good shape with these upgrades. However as we all know she is a thirsty beast which I haven't cared about. With the current fuel prices I am wanting to detune her to lean her out. Let's face it, she's a Commander not a Challenger so while the power is awesome I don't get on it much and need more economy right now. I could probably cut her power in half and barely notice it.
I know how to adjust the VE tables. However I was wanting to know if there is a stoich setting that has a global effect on AFR. Secondly how do you retard spark? I have not played with the spark at all as I don't understand it (give me a distributor and I got it) and don't want to turn my Hemi into a boat anchor.
I'm thinking (and if I'm wrong please let me know) that I should be able to globally adjust AFR and Timing to make course adjustments and then use data logging to fine tune from there.
Any input would be helpful. BTW I would love to at some point take the appropriate tuning classes, I just don't have the time or money and since I am only working on my car I can't rationalize spending what I don't have.
Thank you for your attention and assistance.
Respectfully,
John.

there should be a Fa stoich usually .0688

.0688 is the stoich value for gas , , so it works like this the computer uses what ever setting you have for Fuel>General > StoichAttachment 120550 then add from the PE Table Attachment 120551 to get the fueling value , leave stoich alone , lower the values in the PE table X it all by .90 , go out for a standard drive log it, check for knock, no knock....lower the WHOLE table again in small increments .....same test drive& log lowest I've gone without any Issues was .86 , but Mileage didn't increase any on that truck, it's an 04 RC dually 3500 5.7 Manual 4x2. truck got 10.5MPG before and 10.5MPG after. my Wife's 300 I have the PE table at X.95 MPG went up about 10%

as for Timing , it's more complicated, this is a good video to get a grasp , but some of what he says is WRONG for PreVVT Hemi's engines. the NON VVT react different to timing totals
https://www.youtube.com/watch?v=8g_WZV5EguU

For Mileage concerns what I did for the Wife's car (2007 C300 5.7)was everything on the Part timing table that was Negative I brought up to 0 value , then took the whole table times it by .98 then smoothed the whole table till it wouldn't "smooth" any more.

Buggers, went to edit because of typos and accidentally deleted my earlier response.

Sounds good, thank you. I'll watch the video later today and try your suggestions.
Right now my attitude is 10% is 10%, if I can do better even better.

Thank you. I saw that, but don't understand it. So that leads me to a question. Since it isn't the expected 1.0 for stoich is this just a modifier? If I change it up or down how much effect does it have. I've tried finding something about it so I could understand it, but haven't been able to. I'm probably just not looking in the right place, yet.

https://forum.hptuners.com/showthrea...58447-Dodge-PE

Is a good thread to help you out.

https://forum.hptuners.com/showthrea...tarters-How-To

Is a good one started by 06300CSRT8 , when you have the time to kill read a lot of his post and threads , I learned a lot by reading his stuff. and Sultans replies to other threads.

Awesome. Thank you. I will look into it all.

If the ECM uses a narrow band O2 sensor for CL feedback, then altering the stoich F/A ratio will only alter the fuel trims in CL eg the system will still target lambda = 1 in CL regardless of what you do with the F/A. The fuel trims will just be skewed to pull it back to 1.0.

If you do reduce the F/A stoich then it will lean out the PE OL fueling provided no positive fuel trims are carried on from CL.

The only possible way to run these systems leaner than lambda 1.0 in CL would be to add WB O2 sensors with an adjustable NB simulated switching point output and feed that back into the ECM as the O2 voltage.