It won't really hurt the car since modern cars have knock sensors to avoid engine knock and pre-detonation. But if the owner's manual recommends premium gas, why not just use premium gas? It's not that much more expensive and you will get the full power and fuel economy the car was rated for.  

Might as well use premium the manufacturer knows your vehicle best but I doubt the engine wil blow up tomorrow because you put regular instead of premium.

I’ve been hanging with the premium fuel but with the gas prices rising it’s almost costing as much as it is filling up a truck. Just seeing what other options i could use I’ve thought about just downgrading to mid grade