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My shovel needs it if I get stuck running less than 94 octane - it was a PITA to have to carry on every trip.
My FLHT has 10.25:1 CR (likely 10:1 in the real world) and runs happily on 91, so no need. More octane isn't always better - do you have a really high comp ratio?
I believe if you aren't pinging you don't need it.
Store-bought "octane booster" is a waste of money, that's a fact. It only raises your octane rating a few "points", which means hundredths of a percent. Real octane booster is straight tech grade toluene or xylene, available at paint, home, or chemical supply houses and is not a ripoff. There are plenty of mixing tables on the internet for using them. They are safe - you are already burning them in your fuel. You can easily carryit in 22 oz. MSR leak-proof fuel bottles in your saddlebag if needed on trips.
Ninety per cent or more of us don't need it. In fact less than 91 would work fine if not better for many of us..
If you truly need a boost make your own with toluene and a little MMO.
I had a need for it in a past bike in certain instances and it worked.
All my humble opinion.
Ran out of gas at the house and my Evo prefers 93 oct. Had a bottle of booster, filled the tank with my lawn mower gas and gave it a hit of that stuff. Seemed to work OK. Might have been OK with the 89 oct too. Don't know but it was a little insurance.
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