# E85 as race fuel?

**URL:** <https://forums.speedlife.net/t/e85-as-race-fuel/187529>\
**Category:** PittSpeed Automotive\
**Created:** [January 20, 2007, 8:42am UTC](https://forums.speedlife.net/t/e85-as-race-fuel/187529 "2007-01-20T08:42:16Z")\
**Posts on this page:** 1\
**Showing post:** 32

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**Author:** ![tom\_vito](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/tom_vito/32/6000_2.png) [@tom\_vito](https://forums.speedlife.net/u/tom_vito)\
**Post date:** [January 29, 2007, 3:29pm UTC](https://forums.speedlife.net/t/e85-as-race-fuel/187529/32 "2007-01-29T15:29:10Z")

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> [@19's are gone.](https://forums.speedlife.net/t/19s-are-gone/27590/4):
>
> yet here is what i dont understand. on flex fuel cars–how do they decifer what gas is in the car? as duty cycle, egt, cht, flame properties, etc will greatly differ from the two fuels as they have an entirely different properties. how the hell does the ecu klnow what fuel is in it?

Does it even matter? I mean for a stock car, the ecu is really just trying to get a exhaust output right? All thats going to happen is the mixture will change to meet the ecu’s window of emissions. I think, but then I might be totally full of shit…

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