ACDelco & Bosch iridium are much cheaper and have rebates right now so the AcDelco will be $4.50 each and the Bosch $4 each. Iridium will last 100K in a well maintained car. No need for $10 plugs. I have never seen proof they are better. People will say they are better, but I say prove it. There are three 3800 pontiac motors in my family that have gotten 30 MPG with 100K mile ACDelco iridium plugs. Take the money and get ACDelco wires from rockauto.com. or at least get the Bosch. I will tell you right now, run far far away from any ignition or brake part that says duralast. In my experience wrenching on used cars I buy or cars with friends. Duralast parts fair regularly and your car will eventually stop with their brake parts.