Short ram or Cold air?

I don’t have a very big budget but i’ve heard getting a new air intake would help with my mileage. Should I got with a short ram or cold air and if so, which one? (2013 mk6)

I don’t have a very big budget but i’ve heard getting a new air intake would help with my mileage. Should I got with a short ram or cold air and if so, which one? (2013 mk6)