go to your tuner with 89 almost empty (light on) and have him tune the maps you want - bring a can (5 gal suggested) of higher octane for the performance tune...

I do the same but with 91 and MS103... I have tuner do performance tune with the 91 then retard timing a bit (and a couple minor tweaks) for econo tune - then I pour in race gas for the race map.

If you only want 93 and 89 capabilities you could probably just go with 93 and have them back it off a bit to be able to run lower octane in a different map if desired…. Best thing to do is ask your tuner what he suggests (or what he’s comfortable with tuning on).

JB - your suggestion is good for e-tunes, but I think he's asking about dyno tune.

 

Thanks OCG35, exactly what I was looking for.

 

I was thinking about an e-tune. I still wouldn't put 89 octane gas in my car just to get a tune that I might not ever use. I think most good tuners can take a 93 octane tune and adjust it for 89 octane... unless you plan to race in some kind of class where you have to have 89 octane... that would be different.

Anyway... Good to see the OP getting a real dyno tune... that's the best.

 

I think I'm going to do a 91 and a 93 map, I know it's hard to find anything higher than 91 in some areas (I do a lot of traveling), so I think that'll keep me safe enough.

 

on a NA stockish car, there wont be a difference between a 91 and 93 octane tune thats worth the time and money. Maybe 1 hp by advancing the timing 1/2 a degree.

 

Did you ever get the Osiris tune? I saw your before/after dynos but not with Osiris.