What wheel nuts does my car need?

I bought this car with mags on each wheel, but now have a stockie on one and its loose. Does any one know what wheel nuts i ll need to get?

i don't want to buy the wrong ones a third time.

it's a 1991 ford fairmont ghia

Ford knows, and the auto parts stores know. So go there and ask.

I just checked 2 different auto parts stores and 2 used car price sites. NONE listed the Fairmont as a 1991 model. I then search "Ford Fairmont'. According to Wikipedia, the LAST model year for the Fairmont was 1983. I suggest you double check what you have.

The thickness of Aluminum rims is much greater around the bolt holes than steel rims so it's possible your stock studs were changed to longer studs to compensate for the rims. If you take a lug nut to an auto part store, they'll be able to tell you the thread specs and get you the proper nuts. A nut that allows the stud to pass through it will prevent any issues regarding the thread depth of the lug nut and the length of the stud.