Mixing octane. Bad Idea?

[camilomachado]

Ok..so I am literally itching to install my Predator tune onto an '07 F-150 5.4. I have half a tank left of 89 octane and would like to install the 93 octane performance tune since it is hard to find 91 Octane here in NY city (our midgrade is typically 89).

Can I just go ahead and fill up my half empty tank with 93 and install the performance tune? If not, can I fill the rest of the tank with 93 and install the 91 octane tune since I am mixing half 93 and half 89?

I am not mechanically inclined when it comes to cars, so please bear with this noob as I get used to these mods.

Thanks!
Milo

[mikel]

If you fill up with 93, I'd go ahead and install the 91 octane tune until you burn through that tank of gas. Then, go ahead and switch to the 93 tune.

Thanks

[camilomachado]

Awesome! Thanks for the quick feedback!