There is a gas station near me that sells AvGas to the swamp-boat owners (those flat-bottomed things with propeller in the back that people ride in the Everglades)

I was wondering if adding a little of that to the 93 gas will make my TL-S happier

Back in NY, I used to fill up my GTP with Sunoco 94, but there is no Sunoco in South Florida

 

Not likely, save your pennies. Once you change your timing, then I'd consider it.

 

Yeah, save your money. Octane beyond what you are already using isn't going to do you any good.

 

The AvGas I've seen is usually 100LL (100 Octane Low Lead). It's not unleaded fuel and will clog your catalytic converter and mess up your oxygen sensor(s). Don't mess with it in any late model vehicle. It will be much more expensive than just a gallon on fuel. I'm not familiar with the 93 octane variety AvGas. Either way, I'd stay away from AvGas with the TL or anything with a cat.

Check with some of the local hot rod or speed shops. If it can be had locally, they should know where to get high octane unleaded fuel. It won't do much but drain your wallet a bit quicker.