I know the manual says that there is no point in using oil addatives because it does nothing but raise the price of maintaining the car, but will at fuel addative like an octane booster have any benefit on an S2k? Not so much looking for performance boost (though it would be welcome) just looking for ways to keep my baby in peak condition for years to come.

 

Most octane boosters are bad for your catalytic converter and upper cylinder. They commonly contain a manganese compound that leaves reddish, rust-like deposits in these areas. Unless your car is detonating (computer would retard timing to compensate and you'd lose power) there is no advantage whatsoever from adding octane booster. It will neither increase performance nor the longevity of your engine. Use fuel with an octane rating of at least the manufacturers recommendation and you should have no need for booster.

 

more info: https://www.s2ki.com/faqs/showfaq.php?threadid=17434