I add a bottle of NOS Octane Booster to every fillup. Its a 7 point boost. And then theres a new Enzyme out there that stabilizes your gas so it won't get stale. www.startron.com. It also makes the gas burn better. You can feel the difference when you add the NOS.
trying to win enough money to buy my first Ferrari, and a bigger house. I'll give you a tip. Try the $25 "Cigar" machine in the high roller section. It sits by itself as a slant top mechanical reel machine. That one hits very often, but is rarely played due to the high denomination. I haven't seen any other $20-25 machines with as high a hit frequency as that machine. While I'm no expert in this field, I remember the Subaru forums advising that an octane booster that advertises a 7 point increase will change a tank full of 93 octane to just 93.7 octane, rather than 100 octane. You may already know that though, and if it works for your car, then my point doesn't really matter