Working on MPG

[Fast355]

I'm happy with 500 miles on 30 gallons of fuel at 70 MPH with the 4L80 and 3.73s in a power sucking 10.5" 14 bolt. This tune has towed near 5000lbs 1300 miles back from south florida in 105+ degree heat, dual AC blowin without a single issue. The below screen cap is without EGR, if I had more timing available I could probably utilize EGR even better than I am now.

Certainly not bad for a big block!!! I have nudged 550+ out of the Express a few times on 28 gallons on the open road. Power hungry 4L80E and 9.5" 14-bolt with 3.73s here as well. If I am doing my normal 80-85 mph, I get more like 475-500 miles on 28 gallons, all city I am lucky to get 300 miles to the tank. No EGR here and with my aluminum heads, it really wants more than the 40* of timing I can give it due to the vortec distributor limitations. Will be going 24x coil per cylinder someday.

[ony]

I don't have a wide band set up, I was thinking about adjusting start up fuel and choke decay on my 288 ecm. I was wanting to know cold afr vs coolent temp shows 2.7 at 30kpa would I raise it to 3.0 to lean it out or go to 2.0. then on the choke afr decay, 32 degrezz up is 0.969 would I increase or decrease this numbers?