octane boost for real?

[cghms3]

Hi- I have a 2009 speed 3 with a mazdaspeed cai, mazdaspeed cbe, and a hypertech tune. The gas Im using is 91 octane. Would I gain a little Hp and / or gain some gas mileage (Im getting 20 - 22 mpg) if I added a bottle of octane booster? Thanks!

 

[chief_wiggum]

probably not enough to offset the cost of the octane booster.

 

[MSMS3]

^ Agree.

But 93 octane pump gas may have an advantage, however. I have easy access to 93 octane. I find that with my mods, HT does like the higher octane with insanely aggressive timing advance under high load, high rpm of as much as 18 degrees! The thing zings up top, keeping peak power much longer with very little power taper past 6,000 rpm. Lower octane might cause the engine to pull timing a bit. Since I've not datalogged with 91 octane, I can't say for sure.

I'd say there is no benefit in going past 93 octane, as I am seeing no knock retard under load at high rpm on my datalogging at 93 octane.

It would probably not be cost efficient to add octane boost, but if you can get 93 pump fuel, run it.

 

[cghms3]

Thanks for both your input guys - I guess I will run my tank down to (almost) empty, and find a gas station that has 93 octane - 91 octane is running $4.39 out here in the S.F. bay area - Im so lucky! 93 octane will probably cost around $4.50, but if it helps, I will switch!!

 

[Jdm_Mica]

Fuuuu I'm complaining about $4.06 over here for 93

 

[MSMS3]

93 octane is $3.70-$3.80 a gallon here and 91 is usually not even offered. Lots of refineries close by and lower state taxes on fuel.

But, OP, the slight difference per gallon is much cheaper where you than trying to use octane boost. Might not see any benefit, but give it a try.

 

[cghms3]

$4.06?? Maybe I should move....

 

[cghms3]

Hey MSMS3 - $3.70 - $3.80 for 93 octane??? Who needs California!

 

[chief_wiggum]

I think we're around $4.29 for 93 octane in the socialist rebublik of Illinois; all those taxes to support our incarcerated past Governors...

 

[Badinfluence]

I would say unles it is the Lucas Red Bottled Octane Booster it isn't doing much. The Lucas is about 10 bucks a bottle.

 

[speed3 britz]

Heck, I filled up yesterday up here in Ohio with 93 for $3.54 a gallon. Most all gas stations around here have 93 as the normal Premium grade

 

[cghms3]

maybe I should switch to nitro!!! Vroom Boom!!