So I just scored four alloy rims with tires that come on the newer model j's for $140 and two of the tires are brand new while the other two are still in decent shape. Now I have a 97 cavy running stock 195/65/15 and these new rims/tires are 205/55/16 and I'm looking for some closed lugs but not sure what spline size I'm looking for. Help?

Okay, so thanks to all your replies I discovered that the size is 12x1.5

Post some pics of the new wheels.

Just a friendly FYI, the term spline is usually associated with an axle shaft, pitman arm, yoke, sleeve, etc, not lug nuts or studs. The terminology you're looking for here is thread size and pitch.

The breakdown of our wheel stud is as follows: M12 x 1.5 is a Metric 12mm diameter with a 1.5 threads per millimeter call out. You will see a fine pitch thread on M12 wheel studs, usually 1.5 and sometimes 1.25.

Once I have them on the car I will gladly post some, and thanks for the info just goes to show I still have much to learn.