Regular fuel vs premium fuel

It's not good for the engine and yes you can damage the engine by running regular in an engine designed for premium. Denotation (spark knock) over time will damage the valves and lead to very expensive engine repairs. Premium burns hotter, faster, and cleaner than regular. To save money you can fill up with regular and add a bottle of octane booster to the gas tank at each fill up. I've used STP Octane Booster like this with excellent results. Hope that helps! Jim