What octane for BB tune?

[BlackLac]

So it is my understanding that with the BB tune, it is designed for one octane. I assume that the tune for 93 is best for performance.

I have the 5.3 rwd.
Does anyone have 87 oct dyno vs 91 oct dyno vs 93 oct dyno?
Or 1/4 mile time respectively?

Will 93 get better gas mileage? worth it?

My engine is factory with the exception of a k&n drop in. I plan on keeping it that way for the time being. Should I just do the traditional tune?

I trust the guys on the forum, so I'm leaning towards the BB tune. It also is cheaper that the superchips cortex by 100-200 dollars from my understanding depending on if I send in my core. right?

 

[Grocery Getter]

105ocatane E85------- FTW

assuming you have a flex fuel vehicle

 

[BOSS]

105ocatane E85------- FTW

assuming you have a flex fuel vehicle

I would go for the 93 octane gas, and ask for the 93octane tune. It costs more at the pump, but will give you better overall gas mileage.

E85
I just read this on wiki, so it MUST be true:

E85 has an octane rating higher than that of regular gasoline's typical rating of 87, or premium gasoline's 91-93. This allows it to be used in higher compression engines which tend to produce more power per unit of displacement than their gasoline counterparts. The Renewable Fuels Foundation states in its Changes in Gasoline IV manual, "There is no requirement to post octane on an E85 dispenser. If a retailer chooses to post octane, they should be aware that the often cited 105 octane is incorrect. This number was derived by using ethanol’s blending octane value in gasoline. This is not the proper way to calculate the octane of E85. Ethanol’s true octane value should be used to calculate E85’s octane value. This results in an octane range of 94-96 (R+M)/2. These calculations have been confirmed by actual octane engine tests."

 

[BlackLac]

So 93 is the call. Should I just stick with the traditional tune?

 

[BOSS]

So 93 is the call. Should I just stick with the traditional tune?

Run whichever gas you plan on tuning for.
B

 

[BOSS]

my wiki post was a little sarcastic, but the info suggests that octane calculations for the E85 are erroneous..

B

 

[brndns_hoe]

glad you asked this, I've been debating it too....is the better gas mileage on the 93 octane tune really enough to cover the extra cost on the gas?

or better yet, how much more mpg's are people getting with 93 over a lower octane?

 

[Grocery Getter]

E85
I just read this on wiki, so it MUST be true:

I'll take 94/96 on the E85, we only have 91 unleaded in AZ. I feel my truck runs better in it anyway and definitely has more power not to mention ethanol is not foreign oil.........

 

[BlackLac]

glad you asked this, I've been debating it too....is the better gas mileage on the 93 octane tune really enough to cover the extra cost on the gas?

or better yet, how much more mpg's are people getting with 93 over a lower octane?

Exactly

 

[hoe]

On my 5.3 I can feel a good difference on 87 vs 93 octane. And this was with a stock PCM with 5.3 tune. The stock PCM calibration can tell what octane your runing, and add a degree or 2 of timing. Honestly, if you want more power, and 1mpg increase go with the 93oct tune. If your happy with your current power keep the 87 and keep a cheap full tank.

When a PCM is tuned for 93 higher octane, more timing can be added to the engine without detonation. Yeileding alot more power. If everything is setup right. Dyno tune or street tune... IMO a mail order tune will be very conservative, and have very little timing not to even justify the entire ordeal.

Your low compression 5.3 will not yeild much gains on a 93 oct IMO... Maybe a enthusiast can feel the engine a lil more peppier but thats all. Now my High compression Vortec MAX engine REALLY woke up with my 93 octane street tune. It has tons of timing and fuel.... Its a sensation to drive it at part throttle. I have no need to even get a aggressive with the gas pedal, cause I dont even need to use it.