How lean are your AFR's in cruise

[roadracer380]

I would like to get the best gas mileage I can without creating a drivability issue. I'd like to know how lean other have gotten away with.

[SpeedEuphoria]

around 16:1 easily. Just lean it out in cruise till it stumbles the add a number or 2

[roadracer380]

Quote: Originally Posted by SpeedEuphoria

around 16:1 easily. Just lean it out in cruise till it stumbles the add a number or 2

Really! I tried going to 16:1 and the car had light serge. What is your timing? I'm using the stock SRT4 timing map. Did your MPG improve? If so, how much?

[SpeedEuphoria]

mid 40's in cruise, I have ~8.9:1 CR pistons that are not shaped like the stock SRT4 pistons. So that may make a difference. Also I guess I should have said mid 15's easy, and 16:1 at some points. Also I dont have MS, but you prob need to make it so your TB sense is more sensitive so it adds fuel quickly if accelerating so you dont stumble.

[2K4NightRiderSRT]

Quote: Originally Posted by SpeedEuphoria

mid 40's in cruise, I have ~8.9:1 CR pistons that are not shaped like the stock SRT4 pistons. So that may make a difference. Also I guess I should have said mid 15's easy, and 16:1 at some points. Also I dont have MS, but you prob need to make it so your TB sense is more sensitive so it adds fuel quickly if accelerating so you dont stumble.

This is true. I have cruised on I-75 on my way to Cedar Point at about 16.5:1. My ignition timing was probably mid to high 30s... I should have advanced it more because i could tell it was running pretty warm, but not knocking, backfiring or having any lean misses so I left it alone. Mid 15s is what I normally cruise on around here and on my way to work.

Stock SRT4 motor, 50 trim, MS2E btw.