ok so i was woundering if it is ok to switch between the different grades of fuel?

a little background I have been runnig 93 octane (premium) in my truck for a while and I was curious if I could swithch back to 87 octane (regular). If I do is this something that will mess up my truck or is it perfectly ok. My grandpa say's it is ok but my roommate say's it isn't.

 

Shouldn't be a problem with it... Unless you have a custom tune, 93 shouldn't make much of a difference anyway. Still, I get a tank full of Shell 93 every once in a while.

 

Its not gonna hurt anything unless you are tuned for 93. As high as gas is, I doubt Ill ever be able to put another tank of 93 in my truck again.