Engine/Transmission (1998.5 - 2002) using oil poor milage

[DollingerMasonry]

My truck has 108000 miles on it. Never needs any oil between changes mabe down half a quart in 7000 miles. All of a sudden it has started using a 1 quart to about a 1000 miles. My fuel milage dropped to 15. 5 on the highway this happed almost over night. The turbo is good and clean. Looks like it may have more blow buy then usual. But power seems good and runs good. What could the problem be?

 

[BILLVO]

With the details you gave I would suspect a broken piston ring. Have the blowby tested to see if it in range or not would be a good indicator of a broken ring. Most any diesel shop should have the equipment to check amount of blowby.