5.3 engine with 86,000 miles has suddenly started using a lot of oil. on 2004 GMC Yukon XL 1500

uses about 1 qt per tank of gas on hwy. This veh has no PVC valve to plug up. No sign of leaking oil. No engine noise. Has been serviced regularly. Was bought new and not mistreated.

Asked by for the 2004 GMC Yukon XL 1500
1 answer
IT'S EITHER LEAKING OR SMOKING! YOU SAID NO LEAKS SO IT MUST
BE BURNING OIL, WHY I DON'T KNOW. DOES IT RUN OK? NO MISFIRE
GOOD POWER? YOU SAID NO PCV VALVE BUT ALL ENGINES HAVE TO
BREATH!