Infinite Moving/Rotating Question

I have objects in my game that I need to move and rotate forever. I was wondering what the most efficient way of doing this was. Here are the two that I've tried so far:

     void Start()
     {
 
         _tran = this.transform;
     }
 
     void Update()
     {
         _tran.position -= Vector3.up * _speed*Time.deltaTime;
         _tran.Rotate(_rotation* Time.deltaTime, Space.World);
     }
 
     //Or
     void FixedUpdate()
     {
         _tran.Rotate(0, 0, _rot, 0);
         _tran.Translate(0, _speed, 0, 0);
     }

When using the profiler, it appeared that the Update() method was more efficient, I could be wrong. The object also has a Rigidbody2D and a CircleCollider2D, if that matters.

Thanks!