I'm trying to help people from blowing their shit up? I actually care about the Z32 community as much as I do my Z. E85 is a flex fuel and can vary in alcohol content from around 60-85% Greg safely tunes for the specific alcohol content that you bring him. Yes you can go to the same station and hope their percentage hasn't changed with a new batch. Yes you can mix fuels with a gauge and get it as close as possible to your tuned percentage... but you better be closely watching your widebands and make sure to have knock protection... because it only takes a second of lean to go BOOOOOM!