Offset is how far inside or outside the centerline of the rim the hub is placed. You will want to get this right so it looks right and to be sure it clears the calipers. I don't know the proper dimensions for Maseratis, but I do know that you will want to find out before buying any aftermarket wheels. You'll also need to know the bolt pattern.And what is meant by offset? Is this made to fit the car for each wheel size or how does it work if I want to replace my stock 18 with a better looking 18; is it JUST an even swap out or more to it?