91 non ethanol or 91 with ethanol?

[mnsrt10]

91 tune on truck soon, when they are making the tunes do they make them with ethanol fuel or not? or does it really make a difference ive always ran 91 non ethanol just wondering if should keep running that with the 91 tune or go to 10 percent ethanol fuel. thanks

 

[ARRESTmeRed04]

Won't really matter since they're both 91 octane, the non ethanol fuel is a better fuel though. From my understanding they add ethanol to lower grade fuel to basically boost the octane up.

 

[10-1=9]

Ethanol fuel can separate in the tank lowering the octane. It also absorbs water easily and can damage your fuel system. Unless the system is rated for E-85/Flex fuel & SRT10's are not.