I'm trying to calculate the different octanes I'll get by mixing pump 93 with various ammounts of Toluene in my '69 Chevelle. Anyone know exactly how many gallons the stock tank holds?

---Chris

Both my 66 and 67 have 20 gallon tanks. Mixing in the tank will work the first time you do it but after that you'll have no way of knowing how much of which to use. I tried it. Best to get some containers for mixing. Do you know how to calculate the resulting octane?

Thanks for the reply Pat. If I remember correctly, the calc is (octane x gallons) + (octane x gallons) / total gallons. Is this correct? Also, what's the best way to mix it outside of the tank?

---Chris

That's the correct calculation. I use a Jaz 5 gal jug. I put in 4 gals from the pump and add 1 gal of 108 (results in 94.4 octane) or 110 (94.8), whichever is available. The jugs have gallon markers on them. Probably not the most accurate method but close enough for me.