I have been running 4 Aces in my vehicles for a couple years now seems to work well doesn't color the plugs funny. Works better than some of the stabilizers I have used in the past also. My Haryey sat for about 7 or 8 months last year before starting up on second hit ran the tank out no issues.

I hear ya David. My 300x motors only call for 91 minimum and I think the 300xs is the same also. I would use the ACEs and not give it a second thought. I think more damage can occur from a lean condition from one thing or another than the octane in the fuel on an outboard. Injectors and good fuel flow is key. That is why I have added the fuel pumps on my boat. Actually thought about adding fuel pressure gauges and pyrometers again also.

If the tanks have ethanol resistant epoxy and Mother Mercury says we are good up to 10% ethanol am I going to have my OOSD card pulled for regularly using 93 octane with ethanol? I usually burn the tanks down to less than an 1/4 by Sunday so it does not sit full of fuel and pump it all out over the off season.

Check out Boostane made in west Michigan...invented by an offshore power boat racer and engine builder,----and last I knew it is even endorsed by Keith Eickert.

Boostane is (or at least was ) advertised here on OSO for the last year or 2

Boostane is becoming more and more popular in the racing industry, street cars, and among offshore performance boaters year by year.

You can also get Boostane from Keith Eickert....I found this info and small write-up on Keith Eckert's website.... kustomboltons.com

"We have been running BOOSTANE in our go fast boats and race engines for years. It's the best product on the market right now for reliability, convenience, and performance. We won't trust any other octane booster in our or customer's engines." - Keith Eickert

BOOSTane Fuel Additive

BOOSTane is the perfect option for our Poker Runners out there. Don't worry about getting stranded with out the right fuel in your boat during a Poker Run. Pick up a 5 Gallon Pale today and get it shipped to your door. Have the ability to transform any marina pump gas to Race Fuel instantly. Don't be afraid to run hard and go for that checkered flag, BOOSTane and Lightning Performance have you covered!
•Will raise your effective octane fuel number 15 points!
•Use our very own BOOSTane App to blend exactly to your necessary specifications
•Safe for use with catalytic converters and O2 Sensors
•Safe on all new marine engines with O2 Sensors, including the new Mercury engines
•Won’t settle out of solution and become ineffective in your tank, due to our proprietary carriers
•Perferct for supercharged and turbocharged big blocks and small blocks
•Good protection against the side effects of ethanol on all inboard and outboard engines


I guess, call me a skeptic, but the Eckert site states a 15 point increase in octane - that is 1.5 octane numbers (91 to 92.5).

https://www.boostane.com/

I'm not real sure about introducing unanticipated chemical additives to fiberglas tanks. Seems like that has happened before somewhere, and it didn't work out so well.

Just Sayin'

As someone who is very anal I checked my 28 tanks yearly and they were perfect using Aces IV.
4+ Years.

No question, there is only one product out there that is the real deal & factually proven, and it's more than just an octane booster...BOOSTANE -