This has been thrashed several times. My car runs 11 1/2 to 1 compression. No normal octane booster moves the octane by more than 5 "points" ie .5 of 1 octane. Basically a waste of your hard earned money. The answer, IMO, is to use xylene or toulene just like the
oil companies use in race gas. You buy it at any paint store.
10% (1gal toulene or xylene) plus 9 gal of 93 octane gives you a true 97-98 octane. That is what I do and have no problems with detonation. My motor puts out around 1.8 HP per cubic inch so it needs good gas. I buy either for around 6 bucks a gal so my average 93 at 1.50 a gal gives me 13.50 plus 6, 19.50 divided by 10 or 1.95 per gallon mixed. Works great and keeps everything immaculate in the engine.
MAKE SURE YOU MIX IT IN A CAN FIRST. DO NOT SIMPLY POUR THE CHEMICAL INTO YOUR TANK IF YOU HAVE AN IN TANK FUEL PUMP.
PREMIX IT IN A 5 GAL CAN FIRST EVEN IF YOU DON'T AS YOU DON'T WANT TO SPILL IT ON YOUR PAINT>
FWIW,
Bob