:ST:I have a 2016 focus st with 9600 miles. The other day I drove for a trip that's is 2 hours long and I noticed that it sounded like a diesel. At first I thought it was another truck but I passed the truck and the noise continued. I was mainly using only 5 and 6 and occasionally 4. The faster I would go the noise kept on getting louder until I hit a bump and I went away.