What grade of gas do i put in my 2005 cadillac deville

What is your question?

When i press the gas and get up to about 35 40 miles per hour i start to hear a ticking or clacking noise but it stops when i get off the gas

What makes this problem better or worse?

When i barley press the gas after i get up to whatever speed

How long has your 2005 Cadillac DeVille had this problem?

Since 2010