Yes, an octane booster additice would be an acceptable substitute for using premium fuel. Octane number is XXXXX measurement of fuel volatility; the highter the number, teh harder it is to ignite the fuel.
The concern is engine detonation; if you run too low of an octane fuel in a high compression engine, it can ignite too soon under certain conditions, such as on acceleration. This results in a kind of rattling noise in teh engine, and can cause mechanical damage. Try some regular fuel, and add some octane booster; if you hear this noise, try adding a little more untill you find the correct ratio to not have any detonation.
If you cannot achieve this result, tehn try a different type of octane booster, if that does not work then i would suggest returning to using premium fuel.
If you get the octane too high, it could make the vehicle idle roughly when the engine is cold for a while in the mornings; this would be an indication to cutr back a little.
One othjer thing; make sure that the additive you choose is safe for oxygen sensors and catalytic converters, and do not use any additive containing lead for this reason. If in doubt, check with the car manufacturer (dealer service dept or corporate help line # XXXXX your owners manual).
I am sure that with a little trial and error, you can figure out the correct amount!
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