I just changed the plugs in my wife's Kia Rio at 75K miles. The iridium plugs looked perfectly worn, just nice and tan, and likewise were gapped at the .040 spec.
I swapped in the Champion copper plugs and will change them every 25-30K miles. I like changing plugs frequently for a number of reasons. They come out easy for one. But they also give you a good read on how your motor is running. You can tell a lot about what's going on in there just by looking at the plugs. And, I like changing plugs.
I prefer Autolite copper plugs but I couldn't find them for this car.
Your lucky that they are easy to change. The Nissan I have you have to remove the intake. Basically a afternoon project with refreshment breaks instead of Valium. Dealer wants $400 plus parts. The latest addition to the fleet the Transit had Autolite Copper(tried to go cheap as had 179k miles) and it didn't like them very well so went back to Bosch Iridium