which fuel to use?

[Ghost10]

should I be using 89 or the premium 93* octane gas in my 2010 yukon Flex fuel? I figure since its a big v8 it uses the more expensive fuel?

 

[dreww2001]

Wondering the same thing, i use 89 just because I have a few engine mods I dont know if it makes a difference would like to know.

 

[Ghost10]

Wondering the same thing, i use 89 just because I have a few engine mods I dont know if it makes a difference would like to know.

yeah, I found two places that have e85 but their both about 40mi away each way. one is north of me and one is south. I wonder if it's worth it....?

 

[Ex Euro Driver]

Unless you have a tune that specifically needs a certain octane or corn fuel anything other than 87 is wasting money. E85 might give you a very minor power boost but you get worse mileage with it. Stick with 87 for now until motor mods begin.

 

[Ghost10]

Unless you have a tune that specifically needs a certain octane or corn fuel anything other than 87 is wasting money. E85 might give you a very minor power boost but you get worse mileage with it. Stick with 87 for now until motor mods begin.

thx! would adding a CAI be a mod that requires different gas other than 87?

 

[adventurenali92]

I run 91 but I have an LQ4 6.0 and it runs better when I run 91. Everyone says unless I have a tune for 91, than 87 is fine but my power is noticeably different and mileage drops a bit when I run 87. So I stick with 91. But 87 is completely fine for the 5.3s.

 

[Ex Euro Driver]

thx! would adding a CAI be a mod that requires different gas other than 87?

Only if the fuel mapping curve is altered. Thats something Blackbear Tuning can do for you.

 

[08HoeCD]

thx! would adding a CAI be a mod that requires different gas other than 87?

No.

 

[NGAneer]

I run 93. About $8 more per tank for me and I'll be tuning for 93 soon. Doing a preemptive strike on the financial adjustment.

 

[Fosscore]

My 06 Tahoe is Black Bear tuned for 93 octane so that is all I run. The 13 Suburban is not tuned and the wife runs 89 octane.