AFR with E85

[BSouders80]

Is anyone else running E85 that can see their Air/Fuel Ratio? I'm running a 6.6L on a Livernois "flex" tune. So 93 or E85 or a blend. I have a tank of fuel now that's probably 80% E85 and my AFR is still running around 14.7/14.8. That # is great for gasoline AFR, or is it really just measuring oxygen content regardless of the fuel? So I should have a 14.7/14.8 on E85 or gasoline if the computer is adjusting correctly?

 

[thatJeepguy]

9.8:1 for e85.

 

[DougDimmadome]

Is anyone else running E85 that can see their Air/Fuel Ratio? I'm running a 6.6L on a Livernois "flex" tune. So 93 or E85 or a blend. I have a tank of fuel now that's probably 80% E85 and my AFR is still running around 14.7/14.8. That # is great for gasoline AFR, or is it really just measuring oxygen content regardless of the fuel? So I should have a 14.7/14.8 on E85 or gasoline if the computer is adjusting correctly?

It's likely that your ECU is translating the AFR from lambda to the stoichiometric ratio for gasoline and displaying it that way. I would send an email to livernois but I wouldn't worry about it.

Lambda is just a measure of how close the combustion ratio is to it's perfect stoichiometric ratio, and is usually reported as a value with 1 being the perfect ratio. This does not matter what type of fuel is being burned, just how efficient the burn is. 14.7:1 would be 1.0 for gasoline, and 9.7:1 would also be 1.0 if running pure ethanol.