Are the Iridium spark plugs better than Platinum? The gap seems to change

Thanks for your reply about the spark plugs. My truck gets terrible gas mileage, I was hoping these Iridium plugs might do better. I tuned it up at around 100000 mi. and it didnt help the mileage at all. I guess maybe I will have to live with 10 MPG. Thanks

There are a lot of things that affect gas millage. The vehicles computer would need to be checked for any sensors that may be malfunctioning or any intake leaks that would cause excessive fuel consumption.

Thanks for the info. I will be sure to check for vacuum leaks and get a computer check., R.W.