30 yrs old is none ethanol , may be sour with octane dedrigation . May burn , doubt it will run effectively in an engine . If it was E10 it would be 60 % water !I did not get to it last night but I will get to it soon, I figure I will pull some out and take a pic in a mason jar. There have been folks in this thread that say it will not even burn but I have to disagree, I have a 300 gallon bulk tank that still has a bit of gas in it from 30 years ago also