Are there any octane boosters that actually work?

[Rusty Shackleford]

Asking because I'm planning some mods soon, and a tune. Will be tuning for 91 octane because while I do have 93 everywhere here around the house, I do roadtrip the car and get into areas where 91 is premium. Even then I question the octane ratings because, sometimes, a couple tanks of 93 after a road trip I can do a fuse pull and tell the difference.


Just wondering if there is a booster I could use that might make up that 1-2 points rural fuel might not be making?

[Mr_Draco]

Not worth it.

Most octane boosters you can buy only raises the octane 3-5 points so you would be going from 91 to 91.3-91.5. There are a couple that will give you the 20+ points boost in octane that you want but they are designed for racing engines and contain a chemical called MMT (Methylcyclopentadienyl manganese tricarbonyl) that leaves deposits and is harmful to normal engines (MMT was originally part of leaded gasoline which today's engines can't handle) so they are not recommended on normal vehicles, not to mention expensive as hell.

[CamaroDreams76]

Yes VP octanium, Boostane and Torco actually work. My friend with a ESS supercharged S550 uses boostane. It dynod 720 with pump 93. Added boostane, same day within 30 minutes dynod it again 770. It was actually adding timing over what was commanded.

RPM has some videos of testing the VP booster.
https://youtu.be/PrrxGZMYOxE?si=5KGBQReNOr58Fj9h
https://youtu.be/SJZjNW3ZPx0?si=2213h11XAID4W1wC

As Draco stated all these have MMT. It coats EVERYTHING a rust orange color. Its extremely hard on o2 sensors and spark plugs. MMT will also clog your cats if you have them. If you plan on running it every now and then it wont be a big deal. But as stated those 3 are by far the best on the market. Torco will separate over time where boostane wont. VP octanium is the newest to the market but works.

[gtstorey]

Originally Posted by CamaroDreams76

It was actually adding timing over what was commanded.

Not sure how that would happen, and adding timing over commanded is not a good thing.

[CamaroCracka]

I keep a couple cans of the VP Octanium unleaded version around just in case I want to roadtrip somewhere I am not sure of the available fuel quality. I used it when I saw KR issues in a scan to get by until I could get to the tuner and it definitely turned the inside of the exhaust brown/orange. It also helped bring down the KR number.

[CamaroDreams76]

Originally Posted by gtstorey

Not sure how that would happen, and adding timing over commanded is not a good thing.

On our 5th gens and even the 6th gens yes. On a S550 mustangs, they have a factory wideband and will compensate on a much larger range. His car commanded timing is only 8 or 9 degrees. We were seeing the car add 3 degrees over that after boostane. Picked up 50whp.

S550s will add timing over commanded if you have the fuel (octane) for it.

[gtstorey]

And how does the ECM know the octane? It will have to be running reduced timing based upon knock and increases as no knock is detected. I would not consider that as running more timing than commanded. Not sure where the wideband would come into play on this unless there is added retard based upon assumed knock based upon leaner AF, which won't change based upon octane.

[CamaroDreams76]

Originally Posted by gtstorey

And how does the ECM know the octane? It will have to be running reduced timing based upon knock and increases as no knock is detected. I would not consider that as running more timing than commanded. Not sure where the wideband would come into play on this unless there is added retard based upon assumed knock based upon leaner AF, which won't change based upon octane.

Google search can do a better job than I can

S550 Mustangs, particularly with the 5.0L Coyote engine, can add timing over "commanded" base values due to the sophisticated High Degree of Freedom Executive (HDFX) engine management system, which operates in closed-loop to maximize efficiency and power. It uses knock sensors to analyze octane quality and environmental conditions, adding spark advance beyond the base table if optimal conditions (e.g., high-octane fuel, low intake air temperatures) allow it to safely achieve Maximum Brake Torque (MBT) without detonation.
Key reasons for this behavior include:
Adaptive Spark Mapping: The ECU operates using complex maps (Borderline and MBT) that are constantly shifting based on real-time data, not just a static command.
Fuel Octane Sensitivity: High-octane fuel allows the engine to add ignition timing (spark advance) to increase cylinder pressure and power without pre-ignition.
Environmental Factors: If air temperatures are low or air density is high, the ECU can safely add timing to improve performance.
Correction Tables: Spark advance correction tables modify the main table to reflect optimal conditions, often resulting in higher timing than the base mapped value, particularly if the engine hasn't reached its torque limit or knock threshold.
This dynamic system allows the S550 to constantly adapt to driving conditions to find the optimal power balance.

[Moto-Mojo]

I guess it depends on the definition of, "work." Lucas, which claims to be a "real" octane booster, actually works. And by that I mean, I can feel more responsive acceleration, smoother idle and...slightly better gas mileage. Not really chasing that aspect but it's a byproduct.

However, I'm stuck with California's 'designer blend' crap at 91 octane. So anything is an improvement! I don't use it very often and did notice an orange tint to the porcelain on the plugs last change.