octane question

[final nest]

I know octane levels mean nothing for power or mpg its all compression based. I'm struggling to find info on what octane level to use in my 98 mustang v6. I don't know if I use 87 89 or 93. If I can get a clear answer then that would help. Also in addition to that question. Is it bad to mix octane. Let's say I already have 87 and I decide to put 93 in. Considering that it would in theory give me 90 octane. Would mixing it until I eventually get pure 89 or 93 would that be fine as well?

[wooden flicker]

i think those run 87 but you could always run 93 just to be safe it wont hurt anything at all to mix them

[final nest]

Thanks for the swift response. I'm thinking of running 89 Oct as it'd closer to my 9:1 compression ratio. 10 points per 1. So 90 Oct in theory should be the golden ticket. I may be wrong but I'm willing to be corrected. 89 is basically 90 lmao

[wooden flicker]

yeah you can just run 89 octane and you should be perfectly fine just fill the rest of the tank up with 89. octane is more of a serious concern on boosted vehicles since they are more sensitive to predet than N/A vehicles are.

[final nest]

Also I have a 97 mitsubishi eclipse manual GSX I bought a few months ago at 500 hp. It's modded. I'm running 93 but I was wondering since it's modded if getting a E85 tune and running E85 would be fine if you know the answer. As for the mods it's a big turbo and I forgot the rest 🤣 bought built. Wish I could have found one stock

It's an I4

[wooden flicker]

e85 if very benefitial it allows for cooler engine temps and higher power due to more knock resistance i would do it but you are also still in the safe range on 93 at that power level youd need to figureout if you have enough flow in your fuel system to be able to push the extra fuel for e85 but you could always do an e30 mix tune which is the cheaper route in general the benefits of e85 with the majority of the mpg of 93

[final nest]

Thanks. Maybe a fuel pump upgrade needed soon?

[wooden flicker]

maybe but it depends if it has already been done the two things that would normally need to be changed are the fuel pump and the injectors then your should be set. but at the power level im betting they have been changed but it depends on how much headroom the previous owner payed for

[final nest]

Thanks a lot it helps. Last thing I need is gas to burn off faster than need be. Have a good day and thanks for the info

[wooden flicker]

yeah no problem at all!