Should I use premium gas instead of regular gas

You should use what ever grade of gas your vehicle calls for.  Regular gas with an octane rating of 87 can be used in many vehicles.  However, some vehicles, usually sports cars require premium gas with an octane rating of 91 or 94.  The biggest difference between the two is that regular gas can have up to 10% ethanol in it where as premium gas does not have any ethanol in it.  If your car requires regular gas (87 octane) you aren’t doing yourself any favours to put the expensive gas in but if you require premium gas then you shouldn’t cheap out and put the 87 octane gas in.