premium fuel?

I just bought a '94 J30 a few days ago and I see it says "Premium fuel only" I dont think premium fuel was $1.71/gal in 1994 but it is now and thats a lot. how important is it that I use Premium as apposed to regular unleaded. I have no idea what the previus driver used. does everyone here use premium? could I go back and forth? I will continue to use premium untill I find out if unleaded will work fine. All comments will be apreatiated, Thanks

don't use regular gas unless you don't want your car to run long.

A lot of people will say that it doesn't matter. I think that my J30 runs better on premium so I never put anything else in it. Put a tank of cheap regular gas in once and wound up with fouled plugs and injectors. Only buy gas at nice, respectable stations!