What is the influence of E5, E10 fuel on lambda value?

If you use fuel like many countries in Europe do that’s mixed with Ethanol (E5 up to 5%; E10 up to 10%) would you then have different lambda readings? As far as i understand it, different types of fuels introduce different levels of O2 into the combustion. Does this mean a stochiometric combustion of pure gasoline compared to a stochiometric combustion of gasoline+ethanol delivers different residual O2 levels then read by the lambda sensor?
I know that in theory the residual O2 Value should be 0% in both cases, but I read that in practice a value of around 1% is used for gasoline as the corresponding lamba=1 value, since a real combustion never uses all the O2.
Do I get different readings from the Sensor when using E5 instead of pure gasoline?

Lambda is universal for all fuel types.

Suppose your engine runs safely and produces good power with gasoline @ 0.8 lambda. I assume that if you run E85 that you can run higher lambda values and still be safe due to the increase of fuel to cool the cylinders, so maybe you aim for 0.9 lambda.

An analogy would be ignition timing, I suppose that E85 takes longer to burn since there is more fuel so optimal ignition timing for E85 would be advanced WRT gasoline. 1 dregree of ignition is still 1 degree of ignition regardless of fuel type just like 0.8 lambda is 0.8 lambda regardless of fuel type but for different fuels your target lambda and ignition timing will be different.

Also, just in case you’re still worrying, the same is true in the US. Ethanol can be added up to 10% in most places and usually is.

Thanks! Since I’m gonna use the wideband sensor on my motorcycle and with only E5 I don’t need to worry then. But out of curiosity why would there be an increase of fuel at the same lambda when using E85 ?

Also since i can’t reach you via e-mail, I ordered SLC Free 2 + Bosch LSU 4.9 on 22/3/ but still didn’t receive it or an order confirmation. (#8256) When can i expect it?

Ethanol has lower energy density than gasoline.

Your email has been replied to.

Hey, I still don’t know about the state of my order?


PM sent to you


Alan To

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