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Hello, if i am running lets say 93 octane, how could i raise octane to 95 or 97? Moroso octane boost? E-85? Other? and if have 5 gal of 93 how much would i add?



Mixing in E85 will increase octane but reduce energy value. If you are running a carb, that means bigger jets to put more fuel in. Without the bigger jets, it will be lean and may make detonation worse. Once the tuneup was dialed in for a certain mix, you would have to be consistent from tank to tank which is hard.

Mixing race gas is a proven way to boost octane. Or convert to E85 with a dedicated alcohol carb and tune.