i sinclair station next to the store i work at sells 91 non oxygenated gas.

ive been told that its better for the small engines we sell. What about for my car? would it be better or worse than regular 91 for a carbed 350?

 

Oxygenated gas usually means it has a small percentage of ethanol mixed in it. Usually no more than 5%. The ethanol helps lower emissions because it burns slower. With the BTU energy of oxygenated fuels, you have reduced energy density resulting in increased fuel consumption. You can make a bit more power but you'll also be burning more fuel to do it.

There's also a factor of blending. Each time the gas station gets refueled, there's no guarantee the mix that's going into the tank is exactly the same as the last batch. At least with a non oxygenated fuel, you know the fuel is very close to the same for every batch.