[Smitty_89]

I may be wrong but I think cars nowadays have technology to detect the use of lesser gas and the engine performs accordingly, so yes you get lesser performance but I do not believe you can damage or hurt you engine if you went with lesser gas for a few weeks or something. I would of course never do that and would always buy what the manufacturers suggests but its not the end of the world if you accidentally fill up on lesser gas once or twice.

Edit: I was wrong, so ignore everything I said. lol