What gears are you running?

 

How in the world do you manage that?

 

I'd put money that he's not running 4.10 gears.

I've run several setups and have always kept a close eye on gas mileage - I manually calculate it at each fillup.

Stock LQ9, 3.42s, 4l60e - 23.5 mpg highway
Same setup, with 4.10s - 18 mpg highway
Same setup, switch to 4l80e - 17 mpg highway
Add mid 220s cam - 15.5 mpg highway
Towing 3200 lbs cruise set to 80 - 14 mpg
Turbo kit, E85 - 12-13 mpg highway


To be perfectly honest with you I'm no longer interested in my gas mileage since I barely drive to and from work and that's it. E85 definitely isn't the way to go if you're concerned about mileage. But, if I swapped back to 3.42s or even 3.23s I have no doubt I'll be seeing close to 20 mph highway again, with E85.

 

I bet he is running in the 50s on timing while cruising.
wondering about AFR tho.

 

3.73 gears. Mid 15s AFR, 45-48° timing.

 

Thats a lean cruise for sure with 50% E85.

 

Ahh, well I suppose thats a bit misleading. My wideband for some reason converts the lambda value into a scale based on 14.7 being stoich. Not sure why, didn't care to look into it, just kept it in mind lol. So really, it would be like 12.9 AFR considering the E85 in the tank.

 

Yeah. I understand that. My wideband gauge does the same thing. It only shows AFR based on the gas scale. But I dont really think in terms of AFR anymore, just lambda. Its easier when you're dealing with other fuels and fuel mixtures. My wideband will only read to 1.10 lambda.

 

4.56 gears and a 5500lb truck. 15.7 afr cruise and 31-32* timing

 

the best ive seen is 14-14.5 my tune is way off and i have a problem with my foot falling to the floor on the gas pedal, hope to get my tune changed soon id like to cruise down the road at around 15.5 AFR and then fuel a more when in boost, its all in the tune