I certainly hope you would be running high octane gas in a FI engine...

 

I noticed bad gas. So use gas with invinci clean. High grade gas cost more but help keep her younger

 

no harm will come but if you want to do your car some good get a bottle of seafome and put a 3 of the bottle in the oil a and the rest in the tank it cleans anything that gas runs through and when it is put in oil it cleans ports, lifters, and cams i use it and i have an 82 accord mint with 237,000 +

 

Not exactly correct. The only difference in grades of gas is the amount of octane. Gas either has 87%, 89%, 91% or 93% octane. The higher the octane, the more resilient the fuel is to spontaneous combustion (aka detonation/knocking/pinging). This is why diesel engines don't need spark plugs. Diesel fuel will spontaneously combust at high pressures.

High grade gas is only for high compression engines.