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i82much · 02-09-2021, 09:04 PM

Do you have a wideband? I think leaning out the cruise AFR will get you the most bang for the buck. Leaner mixtures require more timing, so basically you wind up trying to lean out cruise and add in advance until you reach the point of diminishing returns or where you can’t realistically lean out the carb more without affecting part-throttle performance negatively.

I started to go down this road to get decent fuel economy out of my 396 K10, but eventually accepted the fact that, with two small kids, I was going to spend a lot more time in my 2500HD crew cab than in my K10. Not sure how to lean out cruise with a quadrajet but I believe it’s doable.

02-09-2021, 09:04 PM	#18
i82much Registered User Join Date: Jul 2008 Location: Bowie, MD Posts: 313	Re: Timing & Gas Milage Do you have a wideband? I think leaning out the cruise AFR will get you the most bang for the buck. Leaner mixtures require more timing, so basically you wind up trying to lean out cruise and add in advance until you reach the point of diminishing returns or where you can’t realistically lean out the carb more without affecting part-throttle performance negatively. I started to go down this road to get decent fuel economy out of my 396 K10, but eventually accepted the fact that, with two small kids, I was going to spend a lot more time in my 2500HD crew cab than in my K10. Not sure how to lean out cruise with a quadrajet but I believe it’s doable.