NicD

I guess it doesn't really matter to me because in almost all cases the desired lambda isn't changing based on ethanol content and therefore you are shooting for the same value on a gauge showing a gas scale AFR anyways. For example I'm shooting for a high 11/low 12 AFR (gas scale) or a lambda value between .80 and .83 no matter the ethanol content. Use whatever is most comfortable because the end result is the same damn thing with gasoline/ethanol mixes. Now running methanol or some other fuels is a different story because those have much different desired lambdas vs gasoline/ethanol.

Higgs Boson

if you are the tuner and working alone, that's one thing.

if you are online and one guy says that 12.9 is the best AFR but is basing that on a 14.7 AFR and you are running E10 with a 14.1 stoich then 12.9 is not what you want to compare to.....
12.9 at 14.7 is 12.37 at 14.1 but both are Lambda .87

rflow306

That is exactly how i have it on my car and in my opinion the easiest way. If someone wants to know what my AFR is at wot i tell them the number and say it's on a gas scale.

NicD

Well I guess that's my point, the lambda and therefore the gas scale wideband AFR reading is the same (based on 14.7 stoich) regardless of ethanol percentage since a wideband reads in lambda and does a conversion based on the fuel selected, well for those widebands that have that ability anyways for different fuels based on the different stoich ratios.

ettan47

Thanks guys for all your input, it’s great information for me