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Higher ethanol content on same tune = running lean?

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Hy guys just a quick question,

Having a daynoday this weekend so did a log for some checking. Noticed the engine is running a bit lean.

The car is tuned on pump E85 but i cant get it anymore so i now order E100 and mix it whit some patrol. I remember when i did an ethanol check with pump E85 its readed around E80 on my tester. Now with my own mix its around E90.

Can this course a leaner running engine?

I noticed the pulse-width is even higher on the leaner run and exhaust temperature is about the same. Im running open loop in both logs.

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Yes, a higher ethanol content will require an increase in the fuel volume to achieve the same AFR due to the dramatically different stoichiometric AFR and fuel density. As a guide, you'll normally need to increase fuel volume by around 40% as you move from pump gas (E0) to E85. What this means is that your difference of 10% ethanol (E80 vs E90) could be expected to result in the mixture being around 5% leaner which is pretty much what your log is showing. The slightly higher injector pulse width you're seeing is likely the result of some other background compensation that's different between the two logs such as IAT perhaps.

Thanks Andre really appreciate your fast replay!! I already thought it was the course but i'm never really sure with the stuff i figure out myself :P

Here is the movie of the run i made to get some logs. It was a few days ago but im still evil smiling hehe :)