Calculating fuel octane when using additives

How to calculate your fuel octane when using an octane-boosting additive

It's simple math. You need to know:

The amount and octane rating of your pump fuel
The amount and octane rating of the additive

The formula is:

([Pump Octane] * [Amount of Pump Fuel]) + ([Additive Octane] * [Amount of Additive]) / [Total Amount of Mixture]

Let's look at a real world example ...

You're heading to the track with a 1/4 tank of 93 octane pump fuel. You stop by the paint store and pick up 2 gallons of Toluene to take with you. What will be the octane rating of the mixture?

Evo fuel tank: 14 gal (EDIT: Tank is 14.5, but I'm not doing the math again)
Amount of fuel in tank: 3.5 gal
Octane of fuel in tank: 93
Amount of Toluene: 2 gal
Octane of Toluene: 114

(93 * 3.5) + (114 * 2) / 5.5 = 100.64 octane

sweet!

Matt, I think you need a Nobel prize or something!

No, I need to find Toluene that isn't $16/gal! The stuff used to be like $5. Thanks for the compliment though.