dwtjr3

My dad and i have a 67 chevelle and we do a 50/50 mix of 110/93 octane fuel and we are guessing that it is right around 100-103 octane fuel.

However, i dont think it is worth it for you to mix fuel, because it will be hard for you to keep a consistent fuel mixture in the tank. One week you may have more octane then the next week yakno?

4.6Gtconv

Thank you everyone for you input, I went ahead and called bama I asked the guy what is the difference between the "91" race tune and "93" race tune.. He said honestly its literally "1-2 hp.. So I just had him change my race tune to 91 because 1-2 hp isn't worth all the fuss... Thanks

sonicx

That's smart because running 93 tune with 91 octane will cause you to hear a ping. I know first hand (back in the day).

speedycpu

Just to answer the OP's main question, with a 15.6 gallon tank it would take 3.5 gallons of 100 oct. and the rest 91 to make 93.0 oct.